Is the G2 the plastic one?
Plastic traps heat and can cook the LED.
I think Surefire uses a metal head in their LED version.
Get a low powered dropin or a multimode so you can run in low or medium most of the time.
I just finished asking the same question a week or two ago and did some research on cpf. Seems DX sku 6090 is not believed to generate so much heat as to cook the led. I went this route for my sister's gift as she won't have to think about it. It is surprisingly bright, easily illuminates objects at 100yds. Shines eyes/reflectors much further.
For myself I like the looks of sku 17593... you can have the stock three modes or even a very low mode with the ramping. Even if it does make lots of heat on high you could excercise control and get by I believe. It's on my DX wish list and I will probably try it in a month or so if nothing better looking comes out.
14442 should be just fine in a plastic bezel G2. Use it on low for ~40L, Med for ~80 and sporadically on high for ~135L. I would not recommend 11836, I find it quickly overheats in my M2 without foil wrapping.