Yeah, I still have this saved from the "What parts break in a carbine course" tread on Arfcom (which I now cannot find). This is when someone asked Pat "What manufacturers do you recommend?"
Colt, LMT, Noveske, Sully, new S&W; also any of those lowers with Larue Uppers or BCM uppers.
Makes sense seeing how he does TONS of field testing for BCM, although I've never actually seen anyone using a Sully rifle (not that I've been to one of his classes but MAN I would love to do so!).