The people from CMMG are at most of the Missouri gun shows. I spent an hour talking to them one time. They are very nice, and seem quite knowledgable. I wish they built their own .308 AR platforms (they are dealers of DPMS). I nearly traded them my Olympic Arms toward one of their .223 AR's.
CMMG is awesome to deal with. They have a really good rep in the AR industry and I know they do use DPMS parts but they do much better QC checks than DPMS and I think they make some of there own parts.