Well, as everybody knows, I'm the long standing Armalite guy. I've got nothing but the AR-10B mags......mainly cause all the 10's I've built are the 10B model. I've got, literally, a pile of the B mags. Those fukers may add weight and all (not really that much)..........but I never doubt if they'll let me down. They're tried and true. Hell....I had more issues trying to use some 10 rounders at a "friends" place back in May, then I ever had with any of my 20 round standard mags. (granted....they were new and never used before)
Now that being said. I've got a couple LR-308's that take the PMAG's. I've got nothing to complain about them either. They just work. It's not like Magpul is new to all of this or anything.