I do like my DPMS.
The reason I have it isn't because of extensive research though. It's because it was the cheapest .308 I'd ever seen.
Never had problems with DPMS magazines. In fact, the only real problem I ever had was with broken extractors. Any function problems that come up have been fixable with cleaning.
That said, I've never heard anything good about DPMS customer service. In fact, I once heard that a DPMS representative told a dealer that the commercial market, for them, was "fishing money". That is, they get everything they need to stay in business from Government contracts and the civilian market is just pocket change to them. This was second hand, but from the person it was said to first.
I was really turned off by that.
Their pattern of rifle does seem to have an advantage in that more manufacturers are using it. If you want a 1:10 twist barrel, it looks like pretty much every DPMS has it. If you want an Armalite with a 1:10 twist, it looks like the AR10T, Super SASS, and National Match ( I WANT ONE
), are your only choices. They're good choices. There are just fewer of them.
A cursory examination seems to show that there are more DPMS LR rifles in your price range (at MSRP) than Armalite rifles. Actual market prices are usually lower though, so your mileage may vary.
Is that confusing enough?