I used a CA AUG and JG AUG. My vote is always go for quality(CA).
I've worked on both guns and it was a breeze with that version of gearbox(unsure of which one it is now). Alround I like them, I like their look, the selector right on the trigger(although my JG conked out few times) plus the room for such a looong inner barrel.
The only things that I didn't like were that they are alittle tail heavy and mags are tough to store or even find pouches to fit them.
All in all I like it, hope you find one that works well for you.