The G2 has paid for itself trifold. I've shot over 4000 rounds with this set-up and still have the original bulb in it. I'm going to get another one for a new build and epoxy it to the FAS-2 mount. Mine is a little loose and slides on occassion about a 1/4".
The upper is my Bushmaster I built last year in my basement. KAC hand guard I got from an SF guy. Vertical pistol grip I got from Combat_Diver in 2002 when I was in Macedonia. Aimpoint ML2, Arms mount and BUIS from Rampart178. Buttstock is CAV Arms Coyote Brown. Sling is Spec-Ops brand "Mamba" sling. Flashlight is Surefire G2 and mount is Samco FAS-2. M16 bolt carrier assy is DPMS.
The lower is good old Army issue Colt M16A2.
I've built or helped order, 14 M4 upper conversions in the last 7 months. I got SF, 18Bs coming to me for M4 builds and mods. (Yeah Combat_Diver, I'm yanking my own chain).
The ATV was a loaner. My usual ride is a Polaris Ranger UTV 4X4. I fried the engine and had to replace it, then the battery let go. Should be up and running tommorrow.