Top positive review
Overall happy with this bulb
Reviewed in the United States on March 25, 2015
I have bought 4 of these so far since they seem to be the most preferred on amazon. I genuinely like them for how they work. I have not used them for an extended amount of time yet so I cannot speak for longevity. But out of the box, they are very bright and stay lit without pulsing or flickering. The ad says the light is 4,000k but I honestly think it's around 3,500k myself. I would prefer it to not be any lower than 4,000k as It will be used for outdoor lighting. So that takes off a half star.
The other half star will get taken off for a defective bulb I received. Yeah it happens, and if you catch it soon enough you can do a hassle free exchange so that's good. My defective bulb was not as bright as the other 3, and once fully warmed up (after about 5 minutes of use) it would turn from a 3,500k color to an orange color for 1 second, and back to white. 30 seconds later it did it again, and again, and again, and so on. The new replacement is just as bright as the rest and works fine in the exact same fixture, so I can't complain too much. Overall very happy.
One thing to note as some seem confused, this is a bulb rated for enclosed fixtures only. If the glass at the base of the bulb is too wide to fit in your socket, you need an open rated bulb. I'll post the open rated version of this bulb at the bottom of my review. Some open fixtures still allow these bulbs, but they really aren't supposed to, and you do loose 500 lumens for the open rated bulbs which is unfortunate.(this is due to their additional layer of thick glass) The reason for the open rated bulb is because halide lamps sometimes explode at the end of their useful life, sending hot glass in almost every direction. You can imagine this would be very dangerous in, lets say an automotive repair shop that may be replacing a gas tank. Vapors build up over the floor and will ignite.
I will share though, fixtures that are open but are over cement outdoors are pretty safe to run these unprotected lamps. The advantage is they are 500 lumens brighter for the same amount of power. You can modify the base of the open fixtures by cutting the porcelain down far enough for a regular halide to fit. You have to score the porcelain where you want it to break, then use cutters to crack it along your score. I've done this to my fixtures where it is safe to run an unprotected halide.
Open rated 100w Sunlite metal halide(to fit those longer narrower porcelain bases): http://www.amazon.com/Sunlite-MP100-MED-100-Watt-Halide/dp/B004QWYMKC/ref=sr_1_3?ie=UTF8&qid=1427344890&sr=8-3&keywords=100+halide