Well I can see your doing your research. I guess your not considering the dpms anymore?
I had an Armalite, and now I have a Armalite lower with a Bushmaster upper. I've never had any problems with either except for the fact that my Armalite upper had a "SAMMI" chamber. This was great if I used good quality .223 ammo. It didn't like the nato 5.56 ammo.
I would have to say that your not going to go wrong with either. Just be sure of what your going to use it for, and ck out what is what. Most manufactors are going to have a nato chamber for the 5.56 stuff. I think that quality has evened out across the board in the last couple of years. Find a dealer you like and really discuss it with them. You can ask me who I recommend and I'll tell ya.
It is who you deal with that makes a difference in my humble opinion.
hateCMMG they seem to be good to work with, and they know there stuff.