Can't really think of anything that will hurt your AR... Most of what I shoot for recreation is wolf, the good wolf not the lacquer coated stuff... For anything else I will upgrade to better ammo... But as long as you take care of your rifle not a whole lot that will do much harm.
Some of the stuff they make is amazing, especially the match stuff. You start getting into their bulk stuff it can be good plinking ammo, but you won't be winning any precision matches.