I like 'em, I've never run one on my vest in a game, but I've tried them out before, and they fit AEG, GBB, and real-steel mags equally well, and seem to hold on quite well too, but give up the mag easily enough when you tug on it. Of course, that was the real-steel, ITW-brand FastMags, so I can't say how good the copies are. I'm torn on whether to get a set for myself or not, but that's just a matter of whether I want hard-shell mag carriers or something that's soft and flexible when empty.