I haven't had one blow yet and I have a lot of use on several (an EO-9, HO-9, and HO-4). Everyone has had varying experiences, overall they are pretty positive with a few premature failures here and there. The rate of premature failure might be slightly higher than with a SureFire bulb, however, the LF bulbs are being driven harder, so it is reasonable to assume that they SHOULD have a higher failure rate because you get to enjoy slightly more lumens per watt. Keep in mind that SureFire rates their lamps for 30 hours life, while LumensFactory rates 20 hours.
To give an idea how the HO-9 compares to the P90, I'll give a number I would expect Surefire to put on this amount of light:
P90: 105 surefire lumens
HO-9: 145 Surefire lumens
It will be just enough difference in output for you to say "yea, that looks a bit brighter, nice" and the slightly whiter tint will also probably make it more noticeable. Don't expect to be "BLOWN AWAY" by this amount of difference... But I think you will like it, the HO-9 is one of my favorite lamps. Perfect balance of beam concentration for the amount of light coming out the front.
I'm not sure about the fit in a G3, but it will work fine in a G3 as far as I understand, on either 3xCR123s or 2x17500 li-ion cells. Someone with more experience with a G3 will have to let ya know whether the bezel will screw all the way down or not.
