I've had one for about a month, but I haven't had the chance to get out and shoot.
I went from a DPMS AP4 (gen 1) to the G2 AP4. My reasoning was to go the cheapest route since I'll be rebarreling to a custom barrel as soon as barrel extensions become available.
I pretty much tore it down and started from scratch.
Upper:
SLR Ion Ultra Lite 15" Keymod
SLR .750" Titanium set screw adjustable gas block
It's still wearing the factory brake, but it'll be getting a Griffin QD device for the Alpha suppressor that's in jail!
Leupold VX6 2-12X42 w/illuminated reticle
Lower:
Magpul STR w/enhanced butt pad and new buffer tube (mil spec)
Hogue grip
Geissele High Speed DMR trigger
Gun feels amazing and is a huge improvement over the Gen 1's. Just hope it shoots as well as my old AP4!
http://rs247.pbsrc.com/albums/gg124/jaso...80&fit=clip