If there's 1 lesson to be learned from "The Great Panic of 2012/2013", it's this: DO NOT EXPECT spare parts to be there.
That, alone, would turn me away from any weapon system that requires proprietary parts in order to function. No piston-system -- certainly none by a small manufacturer as Adams Arms irrespective of how good/bad the quality may be -- will be as prolific as the DI-platform. Parts will always be less available. (Case in point: try to find an Adams Arms replacement piston rod or gas block right now ... from anybody other than the manufacturer themselves). It just is what it is.
Seeing as how this is your FIRST AR, I believe the choice is very obvious.
The AA will do absolutely nothing better than the Daniel Defense (or any other top-tier DI gun). This isn't about the "vibe" -- it is a fact.

