Several threads on this. Most seem to be positive with the occasional, "these are junk, don't ever buy".
I cannot speak for any other of their mags but the STI/SV 2011 mags. When I shot limited last year I had 4 of them in 40 that ran flawlessly in two different guns and never needed to be tuned. I am currently using them in open, 170s, 155s, and 140s. All of them are great as well.