Its hard to say. The few people I know who own colts keep them locked up because they think they are worth big bucks..Colt's quality of the AR-15 was always better than any other manufacturer for a long time.
Everyone lets a stinker out once in awhile. But they had way less of them!
Out of the box. No other AR-15 is made as well as a Colt.
Their 6920 models are the best of their type.
As far as mil spec ARs are concerned IF they are made to specs they will not be any worse or better from one manufacture to the other.