I bought one a few years ago and it needed adjustment. Gas tube was misaligned or bent when it came to me. Chad helped me out and swapped the part (plus some extra while he was at it) in no time and it was running fine. I think I had a thread on it a long while back. The BCG that came with it was not the best and was replaced with a BCM.
Also FSB is very slightly canted, which I don't think can be fixed. Gas ports still line up, and I can still zero without maxing out the windage on the rear sight, so it's not too uncommon, just my OCD. I know other builders can and do get them dead on with much greater consistency though.
I honestly wouldn't do it again and save myself the small headache, but that is just my lesson learned and opinion.