I have a lot of experience selling them as a dealer.
If it were me, and I were looking at a .308 caliber AR-style rifle, I'd choose the DPMS. They are far less expensive than the Armalite and, in my experience as a dealer, of better quality, too. The DPMS guns are known for accuracy. But getting mags come sometimes be a PITA.
But that's just my opinion based on my experiences. I'm sure others will have different experiences.