Hey I'll take the last word then! (Unless the OP wants another crack at it.) Uncle Sam sent me to Vietnam in 1968, took away my M14 and handed me an M16 which I have to say served me well. Yeah I'm an old fart now.
Then I got out in '69 and hardly ever handled an AR style rifle till last summer when I decided to put one together. Don't know why I waited so long but the really annoying and confusing thing at the time was all the magazines and many in forums said you're an idiot if you don't go with a gas piston. Very glad I didn't drink the kool-aid and am pleased with my new/old friend. If someone else wants a piston AR, fine - but in most applications there's little to gain.
Anyway, Mosh and Hillbilly68 we're all on the same side and are vets so let's stick together! I bet we'd get along pretty good over a night of beer and pizza and swapping war stories. Oh and I'm an old hillbilly from NC so watch what you say about us, Mosh!