I love Bushmaster. I also like Rock River Arms. I will say I like the coating Bushmaster uses inside their uppers. The RRA upper I've got showed light wear inside the upper after only a few range visits. The marks are cosmetic only and are INSIDE the upper. Not like you can see them from the outside.
That said, I really don't think you can go wrong with one of the better manufacturers like BM, RRA, Colt, etc.
BTW the RRA upper I've got has a BM light-weight 20" gov't profile barrel. I LOVE it. I'm sure the 16" are just as nice.
I bought my RRA/BM upper from a friend who had Pete in NH put the whole thing together for him. If you're not willing to tackle putting together an UPPER (the lowers are a piece of cake), I'd suggest getting the whole thing from BM. Otherwise, if there is a problem you have to deal with the guy who assembled it and potentially two other manufacturers. Plus all the shipping costs/time.