I like my Rock River as well. I went to a shop that stocked several brands, including Bushmaster, and Armalite (and others). They had about 50 ARs on the racks.
If price were a MAJOR factor, I'd have picked a plain Bushmaster. The Armalite, my number 2 pick, had a nicer trigger pull than most of the guns, but was a plain flattop and had no rear sight. It was green, too, which was different, at least.
The Rock River had the best trigger pull, was a flat top, but with a rear sight, so I can add an optical sight and keep the iron sights (important to me). I liked the feel of the M4 handguard as well.
Only put a few hundred rounds through it, so can't say what long term reliability will be like, but enjoy the 2 stage trigger. I'd buy the Rock River, if I were doing it all over again.
BTW, since the 9-11 deal, his supply of ARs is GONE. Last time I was in he had just gotten a delivery of a few more Rock Rivers he had ordered a while back, and they were all spoken for. The racks were mostly empty, but for the odd lever action, a few Remington bolt actions, etc.
Used to have big stacks of milsurp ammo by the gun racks, and that's all gone, other than the bit of 7.62X54R he stocks. Maybe he'll carry a few Mosin Nagants to fill the empty racks and move the rest of the ammo?