I think a lot of the DPMS bashing comes from people that have never owned one. You hear the same about RRA, Bushmaster, Windham and others.
At least half of the AR15's being used today do not meet the mil-spec, they have 4140 barrels, 8620 bolts and commercial size RE's, but they still run fine. They may have a higher failure rate if you are shooting 2k rounds a weekend at some class.
The AR needs quality..
The rifle the OP is looking at is $820, I think you can get into a PSA for slightly less and have a rifle made from better materials, but you have to deal with ordering and ffl transfer.
For my Viet Nam era look alike I found a cheap Bushmaster A1, I changed out the furniture set to the early style and changed the flash hider. Close enough for the girls I know. It's been 100% reliable for years.