My views here are well known - if my handle didn't tip you off first, that would be Colt.
But rather than listen to me, a common Law Enforcement Qualified Armorer and Firearms Instructor, have a look at what the "Heavy Hitters" who train the REAL SWAT and Military Operators have to say about all the brands, then investigate for yourself. I will tell you that NO Manufacturer is absolutely perfect, as Whenever Human Beings Involved = Mistakes will Happen. Colt just does it better overall, more consistently, due to their Government mandated process.
The Link for Real Professional Opinions is:
http://www.tacticalforums.com/cgi-bin/tacticalubb/ultimatebb.cgi?ubb=get_topic;f=56;t=000497#000000
These guys have the benefit of seeing hundreds of thousands of rounds go downrange every year from hundreds of different rifles over their Pro-Trainer careers. It isn't heresay and it isn't based on who paid them to say that - in their business, LE and Military, something that doesn't work gets people killed. Their students go in Harm's Way - and kill people there.
I place more credence in their views than Billy Bob's expertise based on owning one Bushmaster he has a whole thousand rounds through - WhoooHoo. Most of these guys basic courses run a minimum of 1500 rounds plus in a 4-5 day class - and that's the low round count side. Most Civilian AR owners have never worked their guns into a sweat - so they don't really know how reliable they are.
As was said during the reign of Ronnie the Great, "Trust, but Verify". (US vs. USSR Arms Control Agreements then.) Read all you can, but examine the source's credentials, experience and commercial interest in weighing the value of a given point of view.
Warmly, Col. Colt