I sell all of these. Quality is pretty good across the board. Now from a service/customer relations perspective, I always end up using Rock River, and recommending it to my customers. 2nd I go with Bushmaster. If somebody wants something different/custom/fancy, then I end up getting them something like POF. DPMS has been good to work with also. Armalite has been okay.
I hate dealing with Colt. Their service sucks. Their attitude sucks. And frankly, after dealing in their guns, I'm just not as impressed as some of you. We've dealt with a bunch of problem guns from Colt. And the way they handled the issue did not leave me with a good opinion of them.