I have no experience with this particular DPMS, but owned a different DPMS as my duty rifle for a few years. Nothing wrong with DPMS at all, mine worked everytime I needed it to and was very accurate.
The GODS of AR will tell you to get a Larue or LMT if you want a good rifle. They ARE VERY good, but you gotta pay up for one of those. I built my last AR from a del-ton parts kit, and with good handloads and a scope, will cloverleaf 5 shot groups at 100yards.
Accuracy with AR's, IMO, has more to do with the load you are shooting and twist of the barrel that whose name is on it. I have a Colt M16A1 as my duty rifle right now, and with my issued duty load, will not hit the broad side of a barn. I believe its a 1/12 twist and 62gr bullets.
Decide what your gonna be doing with the rifle, what loads you wanna shoot, then pick your barrel for the mission and load and you'll have a great shooter.
GregM