Want to get a couple of lowers and wonder which is of better quality?  Or is the quality equel to BM?

Rock River, Stag, and Century Arms lowers (and maybe some others)are all exactly the same unit, made by the same outfit in the same machinery. I've never seen a bad example of any of them. Only the side mrkings are different.

The DPMS lowers are more variable. Most are fine, but they have a tendency at DPMS to not do very good inspections of the finished product, and I have seen bad ones that came out the door.  Also, they're more expensive than the Rock River pieces, on the average.

The Rock River , Stag and Century pieces are usually really snug inside when new, so the uppers will be quite tight at first. After a couple of hundred rounds, they wear in to be a nice snug fit. DPMS pieces are made bigger inside, at least mine was, and they get kind of wobbly after awhile. Doesn't affect accuracy or function; just doesn't feel as good.

Thanks for the information.  I'll go with RR.

I've got one of each sitting here, and the DPMS is much nicer overall. Maybe I just got one of the good ones...

I have used and handled both and I think the DPMS better.  Better fit, finish, and quality.  Maybe I got one of the better ones too.  

my DPMS's have all been tight as hell

I have had both and the DPMS had a better fit and finish...  

Hmmm. Really interesting.  There are threads all over this site with complimentary comments about Rock River's quality and finish, and now three people in a row say DPMS is better---with it's non milspec Teflon that starts wearing off after a year or two of sweat, solvent and weather.

It's not that I don't believe you guys, because I do.  It does just go to show you that one of my pet peeves about DPMS is still true. They get their stuff from so many different subcontractors, that you never know what you're getting until you actually have it and try it

I never said my RR wasn't nice, I just said it's not as nice as my DPMS. I wouldn't hesitate to buy either one again...but only if I could hold them in my hands first.

Quality is a relative term.  The honest answer is that you need to see them for yourself, and make a decision based on your eyes.  A trip to the anodizing house and a batch of weak solution can give you a much different look than a lower you picked up 2 months ago from the same company.  Will they still work, yes, but "eyes on" is the only way to truely figure out what you are getting.