I think the newer C Product mags are okay, at least the ones I purchased mostly from late 2014-16 or so have all worked fine for me. Own at least 30 of their aluminum 30 rounders, just got them from AIM or wherever. At the time seemed to have positive reviews and I just didn't know about the controversy, now I know the controversy.
But just my 2 cents on the actual use of regular mags. Yes I have used all of them, no failures. They also seem to load into my rifles the easiest on a closed bolt (with full 30).
I have since stocked up on Lancers, they are working well thus far. But I'm starting to pick up a few Okay mags now, price being about the same for Okay Surefeeds as C pros anyway. I looked into their E2's, but I don't think it would really benefit me, not really going to ever use M855A1 AFAIK...