The A2 is my preferred AR. I had Bushmaster (Windham, Maine) build me an A2 Hbar DCM gun to my specs years ago, and cloned it on a Bushmaster (Windham) A2 Hbar XM15. That giving me my match gun, and a back up. Shooting Highpower with them, I know the A2 and feel comfortable with them.
The downside today, is that everyone is about the flattops. That makes finding a normal A2 upper a bit of a challenge. I had to pay a premium to RRA just so I could have an A2 carbine. I know they still make the 20" guns in A2, but we hate them now.
I do have a Windham 20" Gov rifle that is very nice, but I hate that it's a flattop.