Generally great bulbs, but they have strobing effect that is headache inducing.
925935
I installed 2 bulbs into a hallway light fixture, and the other 4 into my bedroom ceiling fan. I like that the bulbs are approximately the same brightness and color temperature as the incandescent bulbs that they've replaced. And of course, it's great that they stay cool and use less electricity. These were expensive, though. I bought them mainly to keep temperatures down as we'll soon head into Phoenix's summer season.

These bulbs are taller than typical candelabra style incandescents, but this isn't an issue for either fixture I've installed them into.

The main downside for me is that they are producing a strobe like effect when I move near the bulbs. This is hurting my eyes and giving me a headache. I notice it most of all when I am folding laundry on my bed, which is directly below the ceiling fan that has 4 of these bulbs.
271724
well first off let me say this isn't my first rodeo. I've used all brands, from cheap Chinese imports to home depot cheap Chinese imports and find them of varying quality/life. These have worked well BUT seem a bit dimmer than the ones I've used before. A friend pointed out the difference sometimes is in the filament, but I think they are all the same. For the price you can't go wrong and none have burned out yet. I will update this review if they start going out prematurely. As someone also stated on here, WEAR GLOVES or handle with a  paper towel. As nutty as it sounds, getting your greasy mitts on these bulbs will cause them to blow out prematurely.
1353666
The fitment and color of these bulbs are great in my kitchen. However, these bulbs produce a constant buzz even when the dimmer-switch is in the full ON position.
2238235
I guess if you like the flashing mode they're okay. As others have mentioned, these bulbs don't like to stay in the Fade mode, which is WAY nicer. On my next attempt I'll get something brighter and less annoying.
3482702
I love that this bulb puts out so much light and has such a warm color temperature, but it was a bit wonky. Sometimes when I would dimm it all the way down or back, it would get into a manic state of loud buzzing and blinking on and off.  It wasn't super common, but was quite annoying when it happened.  And it would be a lot more common if I replaced all my bulbs with these.  None of my other (non-Philips) bulbs on the track exhibited the same issue, and I even upgraded to a $70 ELV dimmer and this bulb would still go haywire sometimes.  I'm hoping that maybe the problem was just that I got a bad bulb and that others may not be defective. There was also the minor problem that this bulb is a lot bigger than others.  But I was able to slightly modify my luminaire's retention clip so it fits.  I'm still giving 3 stars since it still might work well for others in different situations.
2495782
First the good news - the lights are really bright and you don't need batteries.

Now the bad news - My biggest complaint would be that the lights cycle through the different colors so fast it is very disorienting and distracting.  This thing should really come with an EPILEPTIC SEIZURE warning.  It would be tolerable if the cycling of the colors could be slowed down, but this thing is just insane.
165669
These look good and do turn on automatically as it gets dark outside.  However---they are a bit too bright for my taste.  I don't like flooding my backyard with so much light you would think you were at a nighttime baseball game....Anyhow--These lights look great off--but on---they are way too bright.  If you turn your gaze towards them at night, be prepared to be "blinded by the light".  It hurts your eyes to look in their direction.  So for that reason---I cannot give it 5 stars.  Now that these lights have already been installed, I have to figure out a way to make them less bright.  Otherwise, I'll have to replace them with something else.
4557332
I like the light from these, but wow do they strobe! I have them in track lighting in my store and the fast pulsating strobe will drive you crazy. I put one regular halogen bulb in each of tracks, and that stops the strobe.
3114843
I would like to give these 5 stars, but they are super bright and therefore require a dimmer, when dimmed, most of them buzz. :(  Such a bummer.  We changed out all of the canned lighting in our house (50 cans total) with these and they are AWESOME, aside to the buzzing.  And yes, we are using an LED dimmer.  We tried them both with an LED dimmer and a regular dimmer...same result.  They produce fantastic light output and they look beautiful in the ceiling.  I highly recommend them if buzzing doesn't bother you or you plan to use them in all their super brightness.
1525786
OK, I am giving this 4 stars, but I did have a lot off issues to get them to work. I installed them on my  sons 2008 Volvo S60. Getting at the bulbs is next to impossible, you have to remove a lot of stuff. So, lots of skinned knuckles and a flurry of cuss words later, they were in. And that is the reason I went with these bulbs, because I was tired of paying someone 75 in labor to change one halogen bulb. So,the moment of truth arrives  and they are no go, flickering and turning off and on. So I then installed their relay harness, still no go. Still flickering, turning off and on and the relay was buzzing. I ran the power directly to a + post and made sure I had good grounds all around. The only other option was the capacitors, which did the trick. Now, lets hope they last, because its a nightmare to access the bulbs. With everything now installed, I still have a bulb failure message on the dash, that I cannot get rid of.
2073091
These bulbs light fantastic when they are on....but when you turn them off they constantly strobe like a strobe light??? I put them in a non-dimmable ceiling fan, but had to take them out....Confused....as there is no power to circuit when I turn the light off. All 6 of them did the same thing...
2921864
Bulbs are fairly bright, slight amber hue (not white).  Black wiring is modern and handsome.  Bulbs are very fragile, you'll probably need to buy replacement bulbs at some point.  I purchased these to light up my back deck.  after putting 3 strands up I discovered the bulbs are too bright to be seen directly at night.  It's uncomfortable for the eyes to have them eye-level 6-10ft away.  We decided to hide the bulbs under the deck banister for ambient lighting and it looks pretty good.

4 stars because of bulb fragility.
1467059
The light output is great compared to the OEM bulbs in my 2006 Subaru WRX.  The one problem I have is that this will be my 3rd set of bulbs in as many years.  When the last set failed they both went at the same time and I had to drive home with the brights on for an hour.  This time only one went but I replaced both at the same time as recommended.  As you can tell I think they are worth the money and effort or I wouldn't be buying a 3rd set.  I'm not sure where the "long life" claim comes from in the Amazon ad but that is the only thing keeping me from rating them 5 stars.  Depending on the location of your bulbs, and the difficulty of replacing them, you might want to consider a "lower maintenance" (longer lasting) bulb unless you enjoy working on car as I do.
3635109
These work fine and were super convenient to order via prime and install 2 days later.  As others have mentioned, these light bulbs emit an irritating low level buzzing sound.  I have 6 of them installed in a fixture in my dining room and the buzzing is, at times, overwhelming.  My young kids are especially sensitive to it and frequently ask for the buzzing to go away.  I will use these until they fail but will definitely find a different product next time.  You may want to look elsewhere as well.
2265524
We thought we'd do the "green" thing by replacing all of our lightbulbs with fluorescents.  I noticed that I was getting horrible headaches--the kind that just keep you from thinking.  Nothing would help them at all--advil, tylenol, even prescription meds.  The doctors even sent me to have a CT of the brain, but didn't find anything.  After about a year (yes it took that long) I read a medical journal account on the Internet about how these can cause major headaches--so we took them out, and put the old ones back in.  The headaches disappeared.  Recently, one of the regular ones burned out and (unbeknownst to me) my husband replaced it with the fluorescent (it was convenient and available) and my headaches returned.  When I mentioned it to him, he told me about the bulb.
I have similar headaches in warehouse stores that use fluorescent bulbs that are uncovered, but when they are covered, it seems to be better.
And of course, everyone knows that when disposing of these bulbs, you must be very careful, as the mercury levels are very high and can make you very sick if you break the bulb.
They use much more material than a regular bulb, and use up much more space in our landfills.  Between that, the cost and energy used to produce them, the mercury levels and the headaches, I think these sorts of bulbs are horrible.
Yes, they last awhile longer than the regular bulbs.  But at what cost?
960068
This bulb's light is outstanding, with a beautiful non-yellowing, non-glaring quality. However it has two downsides:
*the light is dispersed unevenly, and a part of the bulb's casing actually casts a shadow you can see
*It buzzes like crazy when used with a dimmer, no matter what the dimmer's set to. It's like a swarm of tiny bees are in your fixture.
2820905
This is a follow up to my initial review where I had just installed them as the primary bulbs on my motorcycle.  (I just completed a couple of other mods that were keeping me from actually riding the bike.)  These bulbs were not a good match to the head lamp assembly on my Honda. i.e. - they could not produce a 'focused' effect. They were only able to produce a very nice white 'flood' effect. So, as a primary source of night-driving light, I could not use them.  However, they really are bright and the coloring is nice.  They would make a great day-time running light.