Surefire likes using the "tried and true" technology.
That's why they still use Ni-Cad batteries in their rechargeable lights. . .none of that new-fangled NiMH or god-forbid rechargeable lithium batteries. . . . .
They do machine aluminum very nicely though. . . .
Not the first, but first popular ones are LRI with 5mm, Arc with Lux3. While everybody were going from lux3 to k2 the k2 had a recall, that and newbie's testing made most companies start using led's with the ez1000 die instead.
I'd have to give it to 4sevens. He managed to snag a bunch of XP-G's from Cree and it could be awhile before we see any more available to flashlight manufacturers, or they could all have them next week, who knows?
It seems 4sevens is on top of the latest LED's though. His Quark line launched with XP-E R2's, he has XP-G's ready to go in the limited Ti Quarks. He's teased us with the multi-color MC-E. I'm sure he'll do whatever he can to get his hands on the latest and greatest emitters and find out which ones are worth putting in his lights.