Get the DPMS they are fine for range fun, i have a DPMS well sorta have a DPMS its a DPMS lower and a Del-ton upper (DPMS owns Del-Ton) after words you can make it just as reliable as anything else out there by upgrading parts as you have the cash, which can also be offset by selling off the parts that are left over
you can spend as little or as much on parts as you want. but pretty much so a lower is a lower, but crap LPK can be a nightmare,
ive fired over 2500 rounds out of my DMPS with out any failures whatsoever well other than when i used weak ammo and the bolt did not lock back switched to a better ammo and the problem went away,
so far i have changed out the DPMS LPK with a STAG lpk and ive replaced the buffer and buffer spring with an H buffer and new spring, next on my list will be the B/BC but im not in a hurry for that
the only thing to be concerned about DPMS is going to be that the lower is forged reasonably in spec,
don't let anyone here tell you that you need to spend extra money to get a better recognized brand name especially if its going to be a plinketter, get what is withing your budget and build on it. a round out of a DPMS will kill just as well as a round out of a LMT or Colt it will just cost you less