I've got a handful of these for my PT-99, and they're clearly not as good as factory mags -- rougher finish, cheap plastic floorplate, feed lips slightly rough and more springy. However, they work OK for me at the range (I wouldn't trust them for defensive work, though). I do note that on loading to capacity, some of the feed lips seem to spring open slightly, but not enough to affect feeding. They don't drop free as nicely as factory mags owing to the finish. YMMV.
Andrew