I have Had the following Ar's:
Colt Sp1 (many years ago, before M4 existed)
Ruger SR 556 (liked the piston, did not like the heavy trigger)
DPMS Recon
Norinco M4 (liked it, finish not best but gun fine otherwise)
PSA M15
I never had a jam in any of these guns. They all ran 100% and were plenty accurate, more accurate than any Mini 14 I ever owned.
I never used the forward assist once, the only person I ever saw using one was a guy at the range shooting his improperly sized reloads which turned his AR into a single shot that required a smack for each round to be chambered. I moved far away from him quick.
Of all of these for best value, I would buy the PSA again in a second, best bang for buck, excellent quality at that price point.