Interesting. I bought a few after they had been out a year or two, mostly to try to get to work with my .40 conversion. They don't work well for that, but they seem to do just fine in .45.
I know Promag had some issues when they were first introduced. But they had worked through them, posting here on Uzitalk and getting feedback. After those initial issues, they seemed to work well for everyone. I haven't heard much about them lately, one way or the other. But once they got them figured out, I can't see why they would change.
I wonder if you got some new-old-stock mags from that initial run.