Good lights for the some applications
357091
I bought these for under my cabinets and was disappointed.  They would be great for under-cabinet accents but not for actually lighting up the workspace as I had hoped.  However, I've put them under my large desk, and they look fabulous there.  I love being able to change the colors, and I can change them to white and see inside the under-desk storage I have.  They are easy to use and connect, but the adhesive could be better.  We followed the instructions, but we still had to use some clear tape in a couple of places to keep it stuck in place.
2068765
Nice lights but the adhesive is just BARELY strong enough to hold it's own weight so you'll have to use some extra adhesive. Also they labeled the colors wrong which gave me a headache while soldering. Blue is green and green is blue for anyone thats wondering. Look great and not too expensive though.
1859195
Good for lighting in areas that you don't want to have an extension cord could be brighter.
3923441
Bulbs look good and light color is good, as advertised.  They don't quite have the light output advertised but it is close enough.  They do work with a dimmer but there are issues with flickering if you are not using a dimmer specifically made for LED bulbs.  The light quality also has a high frequency flicker that is noticeable when you have motion under these lights making motion look a bit cinematic.
1041976
These lights are decent quality lights, which use solar power during the day to charge a battery.  This means that they don't stay on all night (as the battery will wear down) and the brightness isn't as much as ones that are plugged in.  That being said, no problems yet.  I strung one up around my door area and another around my garage doors.

When the sun goes down, it senses no light and turn on automatically.  There are different settings (blink patterns) and they work pretty well.

They aren't great, but then I'm not giving any money to the electric company... so I have that going for me.
2770228
These are great for certain uses.  The drawback is that the solar panel and the lights are not separable at all, so they have to face a certain way to get the sun into the solar panel, and the lights then face a certain way, period.  Of course, there is a little bit of leeway - they don't have to face straight south, but...
They are motion detectors, so they are not always on at night.  I like that feature.  I put a couple on my deck steps and they work great for that use.
2417981
Picked these up to use in an upward facing light fixture with a need to have light shoot downwards. With most LED bulbs, they have a huge solid base that stops light from shining down - these on the other hand provide a good amount of light downwards.

Downside, the bulbs are not the best quality, the glass moves on them. They are very very dim. Pay attention to Lumen rating as I feel they are lower than what they are rated as. They are also more in the red spectrum than the yellow spectrum.
4336415
These lights are bright and work well. They seem a little weak as if the wire was pulled it would break easy. Mine work fine for what I use them for.
3417417
I used these lights for decorating my desk at work and they were useful for about an 8 foot span. The bulbs are a little more spaced out than I planned so I had to keep them in a tight pattern to show properly. All day use on 2 AA batteries was good, I think I got about 15-18 hours before the red and yellow lights went out and I had to replace the batteries.
2335475
These are the right height for my still life projects and I think they will be handy for up lighting. The bulb reflector combination provides a fairly even fill light when combined with a main light. I wanted to try brighter LED bulbs. Unfortunately they would not screw far enough into the sockets to make an electrical connection. If this limits lighting flexibility or bulb availability, this won't be as valuable as I had hoped. But, at this price point it is worth experimenting.
4867967
They work great, and put off alot of light. I have them for running board lights and put some under bed rail for to light up when I have my door open for my tonnel cover lighting.. wires are very very very small, strip then with care and make a good connection and they work fine. I also silicone the edges and where the wire come out. Good light for the price. I get alot of comments on them.
3527828
Good lights, but not quite as bright as I was expecting.  I purchased these for a chandelier in my daughter's room, and compared to 40 watt incandecent bulbs, the room is now dim.  The light they produce is very white, but all the light goes strait up.. So don't expect any real light to come from anywhere except the upper half of these bulbs.  Almost like a flashlight, not an all around BULB effect.  Just light in the up direction.
158869
The lights put off plenty of light for my engine room on the boat. I doubled them up in a few strategic locations to get excellent lighting. The poor rating comes from the flimsiness of the units. While none of them have failed so far, the feel of them doesn't provide a great deal of confidence that they'll stand the test of time.
1654448
Nice lights. But they don't really charge that well for me and don't last that long.
2770067
I used these to replace the lights i had on my vehicle that kept on dying out. They aren't the brightest to be honest but they do the job. Before buying please be well aware that this item will take some time to ship since it is coming from a different location.
246583
These LED retrofit lights give good illumination, and blend well into ceilings. They are dimmable, and can be set to a wide range of brightness settings. Once installed, I'd probably consider them a four star product. But there are a number of points to consider before buying these.

Pros:
You get a lot of light (1200 lumens) out of an 18 watt fixture.

They are designed to easily replace the light and trim in a standard ceiling recessed fixture.

They use less energy than a 23 watt Feit R40 non-dimmable CFL, but give almost as much light.

Cons:
A Feit R30 standard sized CFL uses only 15 watts, and chances are your total number of fixtures will give you enough light with 15W R30 bulbs.

An R30 CFL might cost under $2/bulb, and might cost less over the lifespan of this fixture.

If this fixture doesn't last its projected lifespan, you are out the cost of the fixture and might be stuck with non matching fixtures. So save your bar codes and receipts for the next 31 years and hope they don't change the design.

The springs look like standard springs, and insert like standard springs--until you inert the hub and attach them to the fixture. Then they won't snap in like a normal fixture. People who have this problem are not having it because they are unfamiliar with this type of fixture. Other brands work fine. If you grab the springs from both sides slightly above where they attach to the fixture, and squeeze until the tops are barely further apart than the part they hook into, you might be able to insert them with ease. But be careful if you need to take them down.

Other:
They might buzz. I installed half a dozen of them and none of them buzzed. I then installed dimmer switches for most of them, and then those started to buzz. So I can't say if it's their fault or if it's the fault of the dimmer switches or combination. But I can say that I haven't seen comments about buzzing in the reviews of my dimmer switches, I have seen them for this product, and it's supposed to be dimmable. You won't hear it with a refrigerator or dishwasher running, and I have one of the quietest dishwashers on the market. But I can't say what the case will be in your home.

They might be too bright. After replacing a ceiling full of R30 CFLs, my kitchen was blindingly bright. With dimmers at half brightness, I get plenty of light. Since modern dimmers are electronic and do a good job of saving money, this might be a net advantage. I don't expect them to use only half the watts at half brightness, but I expect they will use far less than 18 watts and end up being more efficient than the CFLs that they are replacing.

CFL lifespans are based on specific test conditions, and in real life usage, I've found that if they get switched on and off too often, or are used for short periods at a time, such as in a restroom, they don't last very long. LEDs on the other hand generally do have a long lifespan and it's possible that under typical conditions these will last many times longer.

The color temperature of 3000K is between the warm white 2700K of the CFLs they replaced and 4500K bright white/daylight threshold area, which for me is a very good color temperature.

Once installed, unless you have a buzzing problem, these are quite nice. Assuming they last, they should pay for themselves in savings, but not at full brightness compared to R30s. And if you take it on faith that they should install easily, you need to rethink things. Adjusting the springs isn't a formidable task, but being blindsided by something that should install easily could make you wish their website at least had a FAQ.
2938344
For the cost, these are a great set of lights. I personally used them for some cool lighting effects for night photography but found them to be way too bright for my purposes. I'll probably repurpose them in some way to decorate my apartment, as they seem much better suited to that task.