Not trying to upset the AR guys, but is there anything I should consider if I am looking for the most mechanically reliable AR? I realize they need more maintenance, however I want to minimize that requirement. Knowing it will never be a "drop in the swamp, pick up and fire" weapon, I want the best change of it being reliable when it needs to be.
All of the brands mentioned above will be reliable. Another to add to your list of decisions is DoubleStar, here's the one I have: AR Star-15 Rifle .223 A/3