Haha... I didn't reference them by name in my first post on this thread, but I knew Brownells was one of the largest (if not largest) current mag producers. Some of their gun techs came to my school to teach an AR class and one of them said he was tired of shooting full auto for hours a day to batch-test the mags for the military.
However, I have probably a dozen of the Brownells mags in grey and FDE (stamped 09 and 10) with Magpul followers and they have worked flawlessly for me.