Light as a feather - great sound - good value!
356634
I also have Sony DR-BT22A, which I like and were really cheap. These are somewhat larger, but very comfortable.
What I like:
Very comfortable to wear for a long time
Great sound for bluetooth!
Optional wired connection for using on a plane
Folds to somewhat smaller size for storage
Minor Issues:
Recognizes my phone and iPad right away, but always have to re-pair with my Mac
Less than optimal voice quality for phone calls - might be due to my location and carrier
1247163
Great sound! I have to admit, I was skeptical when I saw the size of these headphones, but came away pleasantly surprised. They offer a very full sound from such a small package. Highs and mid-range tones are good...bass is there but not overpowering. I have another pair of Sony headphones (an older pair that were "high end" at the time of their purchase) and I believe these Strada Headphones offer as good if not better a sound than my others. These do not have volume controls on the headphones themselves, but really...who REALLY needs that? Well worth the asking price.
3000149
This player is small, light and sounds great. It is a good value for the price.
3051325
These INSTEN "Folding Speakers" are a surprisingly good value for decent quality portable speakers! We own two sets of these (black) and I am very pleased with the performance of the these compact speakers, especially at the low price these sell for here on Amazon. Here are my observations:

Pros:
+ Folding; these have a very clever design that allows them to fold in to a small cube for easy transporting
+ Good Sound; produces fairly good sound at all but the highest volume levels (see "Cons", below), at least to my untrained ear
+ Universal Connector; the unit uses a standard mini connector, so this can be used with all of MP3 players
+ Power Options; comes with a USB power cable or it can use 4 x AAA batteries. You can also use a 6v DC power supply (not included)

Cons:
- Bad Instructions; like many products of this type the instructions manual is lacking and, in this case, erroneously lists the power requirements as AC when it should be DC.
- Distortion; at maximum audio levels this sounds pretty bad

Misc:
* iTouch and larger MP3 Plays might not fit as well as others in this (see my picture in "Customer Images"), but they will still work if they have a mini audio jack
* On the iTouch, I found the best sound quality by setting the iTouch volume to about 3/4 max and then making adjustments on the unit's volume wheel

Overall, these are a fantastic value for a set of good quality speakers that have the advantage of being able to fold up for easy carrying!

Recommended!

CFH
4555739
These are very light, ultra comfortable, and sound GREAT!  I have been a big fan of Sennheiser products for quite a while, and these earbuds definitely have the quality I have come to expect from them.  The bass is good if you use the proper size gels.  At first, I put on the smaller size and they didn't form a proper seal with my ears.  This caused the lower end of the spectrum to be almost completely non-existent.  I swapped them out with the largest size and that made a world of difference.  These are truly full-range and have a crisp "non-tinny" sound to them.  They are so light, you can barely tell you have them in, and they won't break the bank.  Highly recommended!  Just make sure you try all the seals to find the right size for your ears (these come with three different sizes).
2983929
I purchased these on Amazon without hearing them first.  I wasn't sure what to expect when I received them but I was pleasantly surprised.  They have good bass and clear mids / highs.  Since they are so small and light weight, the bass isn't as good as the Turbines or Beats; however, those headphones are not good for the gym and these are.  I bought them to use while working out and they are perfect for that.  I would recommend them if you're looking for something light weight with overall good sound.  There are better headphones out there but, for the price, I'm happy with the purchase.
991800
While not the most top quality sound, for the money, this unit is great little workhorse.  It's light and easy to wear, has a good battery life and gives really nice sound both through the earphones and the mouthpiece mic.  edited 8/21/17: My best friend stated that the sound quality coming from my end was so good, that I went out and bought him one too! Now our 2 hour conversations are crystal clear and my ear doesn't feel like cauliflower afterwards :)
414624
I work alone for the first few hours of the morning, and I decided to get some headphones to have something to listen to beside silence.  I did a little research, not a whole lot, and decided to get these (I have a pair of Sennheiser from last year and like them a lot).

I LOVE these little guys.  They are extremely lightweight and sit gently on top of your entire ear, but they weigh so little, you'll barely notice them.  The build is not so great, but not a dealbreaker.  The cord is thin, and the plastic on the joints etc feels OK but not super durable.  Just be careful.  Oh, and keep them away from velcro!  I accidentally got one earpad stuck on some velcro and it pulled right off.  But a few dabs of Super Glue solved that issue in a minute.

The sound is what matters, and it is extremely impressive.  Very detailed (I listen to everything from low bitrate internet radio to lossless CDs burned into iTunes), crisp, and a beautiful lower end bass.  I would actually say that they may be colored a little for bass, but for the sorts of music I like (dance, electronica, pop, new age), it's awesome.  I was very impressed when I started listening to them, and so were some of my coworkers when I shared them.

I also own the Grado 320si for home listening (these cost $300, so not a fair comparison) and the Klipsch Image One that I use for the gym.  These Sennheisers are most like the Klipsch, but I think the open air of the Sennheiser makes them more comfortable for lengthy listening sessions.

So I would recommend these without hesitation.  Just be careful and don't drop them or toss them around.  I use mine in the morning and then leave them on a hook in my locker, and I expect years of use from them.  They're a great little set of phones.
2867994
I can't rate on the technical aspects, but I can for sound, and these headphones are keepers!  I had originally purchased a pair by SONY, only to find them way too bassy.  These Incipio NX-110 f 38 offer much better sound, at least for the genres I listen to, which are primarily alternative rock, hip-hop and pop.  The build seems decent, the fit is comfortable for me (my head is on the smaller side of the spectrum!).  Others have commented on the ear pads getting hot or uncomfortable after extended listening, so far, I have not noticed those issues--too busy enjoying my music!  As for noise cancelling, I did not purchase this set for that feature, nor have I used outside yet to be able to comment.  For the money, Incipio has made a great headphone set in the less than $40 price range!
4189214
These sound great! And for the price you can't beat it. I'm using bluetooth headphones for travel. I fly to a client nearly every week for work so I want something that isolates me from ambient noise and has great bass, clear tones, and great battery life. This checks all the boxes! I was really impressed with the battery life and bass. These will be perfect for workouts as well with the form-fitting cables that can be set and hold their position. All in all I'm pretty stoked. I'll see if I have trouble with them on bike rides or active workouts. The ear pieces are a bit heavier than I'm used to, but at the time of writing this review they stay in just fine with the right size ear cushions.
2786910
I bought these mainly for my wife to use while she studies for extended hours. As an owner, myself, of couple high-end headphones, these headphones sound great for the price and are incredibly light.

The first thing I noticed about these is how big and wide the sound stage sounds. In music, this means the stereo sound is excellently represented and for use with video games (mainly COD) it was incredibly easy to both pick-up and identify the direction of footsteps.

The highs are a little bit more reserved than other headphones I own, but at this same time this prevents them from sounding harsh. If you are coming from low to mid level headphones, the bass may also feel a little reserved too.  It's not missing, but it's definitely not ear throbbing.  In my opinion, this is a plus since the bass neither drown mids/highs nor does it tire your ears.

Compared to other headphones, sound isolation (both in and out) isn't excellent, but it's certainly not bad.  When my wife uses them next to me in the library I can barely tell she has music on. When I use them, I generally have the volume up more and she says sound can be heard.  If you're planning to listen at higher volumes in a super quiet setting, you may do better with in-ear headphones but anywhere else you should be fine.

Next, comfort. As for comfort, this is one of the most comfortable pairs I've ever owned (Second only to the Sony MDR-XB500 which have pillows for pads).  They're light and rest comfortably on top of the head (unlike most headphones, the band on this sits significantly forward which keeps them more stable on the head). The pads are firm, but cushy and the velor covering is slightly breathable - preventing stickness that occurs with leather/plastic pads. The clamping for is also pretty minimal which helps them remain comfortable for several hours.

Finally, the construction.  These headphones are mainly built of plastic.  For some this is a con, but personally if you take a little care you won't have a problem. The plastic structure feels pretty sturdy and keeps these headphones incredibly light.  The headphone cable is a little bit light and may snag easily, but if you're mindful you shouldn't have a problem.
1806889
Great sound! The reduction in outside noise is just right. The battery life for such light and excellent earbuds is great. The only thing I had trouble with at first was that they kept sliding to one side if I just removed one. One of the enclosed clips took care of that. The only suggestion I have for the vendor is to have it so you can lock the clips to the earbud cable.
1599344
These headphones are lightweight and comfortable. They are easily adjustable for a secure fit. The volume control contained within the wire is handy. The set comes with 2 sizes of male adapter!  The sound is crisp and clear.
Very pleased indeed at an exceptionally reasonable price!
1362662
So I got these through a different site (that rhymes with coupon) for 25$. They are very comfy and lightweight with very clear sounding mids and highs. Also they have a good amount of bass, no distortion either. I now understand when people say that certain headphones sound warm. These definitely have that warm sound. Granted I am not by any means an "audiophile" and do not own a vast collection of headphones. I just enjoy listening to music. And these wooden cans sound great. Definitely get them if you are in the market for a pair under 30$! Don't think I would pay the list price of 100$ for them, but then again I've never spent more than 35$ on headphones/earbuds...
I've seen all the reviews stating that they've had the headphones snap from the headband so I make sure to grab them by the headband not the actual ear cup. Will update review in a month for durability and if they are still in one piece!

//update 4.10.2016
headphones are still in one piece. I would say they get no special treatment when I use them and they get used for around 9-10 hrs a week. Will post when they break, if they break!
3056756
Exactly what I wanted- extremely portable and good sound!
2569563
I just received these yesterday.  Charged them overnight and connected them by Bluetooth to my Galaxy Note 2 without a hitch and without instructions.  They provide excellent sound (I'm not an expert on sound, by the way) but they sound very good to me.  Probably not quite as good as my $300 Bose headphones, but then, they didn't cost $300, and I'm not that picky. These Logitechs are also lightweight and I like the position of the controls - some headphones are difficult to control because the buttons are so close together.  These are spread out over the earpiece and its easier to find the one you're looking for.  I'll be curious to see how the battery performs.  I believe I will enjoy owning them.
154208
I bought these the day they were released, and have already had an opportunity to use them in a variety of locations, including a number of short flights and a couple of long (10 hour) ones.  To me, a frequent air traveler, the holy grail has always been to find reasonably priced headphones that a) sound great, with good bass response, b) are small and easy to pack, c) are comfortable to wear for a long time, and d) eliminate as much ambient noise as possible.  Until now, no headphones could do all of these things to my satisfaction.  The Bose QC20i headphones come the closest so far to achieving holy grail status.

Sound quality is excellent, as it should be for $299.  They sound especially good when used in an office or other relatively quiet location, with good, punchy bass and very nice highs and midrange as well.

They are dramatically smaller and lighter than my QC15's, which makes them a no-brainer to throw into my briefcase and take anywhere, which, frankly, is the reason I have not used my 15's as often as I would like.  They are just too bulky to carry on most short trips.  The 20i's completely solve this problem.

Comfort is another matter, at least for me.  There is an almost infinite variation of ear sizes and shapes among the population, so I don't think there is any way that a mere three sizes of silicone "Stay Hear" tips can comfortably fit everyone equally well (how could they?).  Indeed, I appear to need a size that's somewhere between the small and medium sizes, and find that the mediums work best for me overall in terms of comfort and noise reduction.  But after about five hours of use on a long flight, my ears began to hurt a bit, and I had to stop wearing them for a while.  I can't really fault Bose or the product design for this, as five hours of continuous use is still pretty good for any headphones. After a half-hour break, I was using them again.

Noise reduction is first rate, better than I could have hoped for with such tiny headphones.  Really, when you are on a plane and switch on the power, the noise almost completely disappears.  I think the effect is even more dramatic than the QC15's.  This is a remarkable achievement for earbud style headphones, and Bose is to be commended for it.  With these phones, you can hear quiet dialogue during movies while in the rear of the plane (the noisiest section), and you can keep the volume turned down to a reasonable level when listening to music.  Interestingly, you can hear people talking around you fairly clearly with the source paused, even without using the "Aware" mode.  I think this is actually a benefit, as total isolation is not necessarily a good thing.

Overall construction quality is first rate, with quality materials used throughout.  The wires feel like they can survive the rigors of portable use, and the overall feel of the product is reassuringly good.  I can see where some of that $299 went.

One minor gripe: The rechargeable battery pack is very close to the headphone plug, so this means it's right next to the iPod or iPhone or whatever player you're using.  It's kind of awkward to hold your player with the battery hanging off it like a dongle, and I've tried bending it around so it rests on the back side of my phone.  It's a bit of a handful.  I would prefer that the battery be further away from the player -- maybe a third or midway along the wire? -- so I could find another place to put it, such as my shirt pocket.

Should you spend $300 for a pair of in-ear headphones?  If you want very good sound quality, high portability, good comfort that does not rquire you to jam something deep into your ear canals while providing pretty spectacular noise cancellation, I'd say absolutely -- it's worth the money!