I've had a DPMS for years and it was originally a 24" upper and I've traded it for a 16" upper just for the manuverablilty. At the 2005 Tri-Gun Challenge, I was the lucky winner of an AR-10 (.308) that was a tackdriver as well and only sold it to get the .204 Ruger.
Needless to say, I'm a big fan of the DPMS line.