I'm 0 for 6 on promags. 1 for a mini 14 that sent the bolt on top of the half fed round and smashed the cases right in the middle. And 5 for my m&p 9 that the base plates pop off of and send the rounds falling and spring and follower flying. All five of them have had the base plates fall off at...
Tapco mags work great as long as you don't run m855. The nose of the bullet would catch the front of the magazine and cause a failure to feed almost every time. Could probably file the inside of the magazine down a touch and be just fine. Both the tapco mags I had for my mini did this and I sold...
Definitely don't buy pro mags. I bought five of them for my m&p and now every time I go to seat them in the pistol the base plate fly's off and sends all 17 rounds flying to the dirt. I like to call it the pro mag dump.