DPMS is more common/readily available. Many manufacturers support the DPMS barrel extension.
Noveske is one of the last few to ONLY support AR10, and I suspect that will change soon.
Also, you can get some nice chrome plated BCGs from DPMS, JP and many others. You get freaking ONE choice with Armalite - Armalite. Sometimes hard to find individual parts, and during the SHTF politics of 2009, AR10 BCG parts were nowhere to be found, apparantly.
I went with an AR10 BCG because I just HAD to have a damn Noveske barrel on my 308 build. Otherwise it would have been DPMS or similar.
And I can attest first hand the necessity of matching bolt/carrier/bbl ext. I bought a brand new chrome DPMS BCG for my Noveske / MEGA 308 build and the DPMS bolt would not lock with a round in my Noveske (AR10) chamber.
It also failed my headspacing gauges I bought.
Whoever tries to mix and match is a fool IMO. Very dangerous.