I do have a few promags. Haven't had any fail me yet. They are a bit weaker than other polymer mags. Before I even took them to the range, I took them apart and coated the inside of the body, followers, and springs with some Remington DriLube (kind of a teflon coating). No failures yet and they have at least 1000 + rounds through them. With that said, they are not my preferred mags, but have taken my abuse thus far.