i just picked up 7 of the magpuls and i love them! good product indeed. they also have a groove that runs down the inside of the mag to keep the rounds lined up right. and they are very strong. i saw a video on internet where they were running the mags over with a truck, put them back in the gun and they worked like a charm. " i found the link for the video....
http://youtube.com/watch?v=4BA-EdEAHVA