I have a handfull of ASC stainless mags in 223, 6.5 Grendel, and 6.8 SPC, all are good. I use them for the extended OAL capacity as mentioned above.

The only complaint I have about them is the angled floorplate; it works fine but has a very 1980's/90's style that just looks dumb IMO. That's a very minor gripe though.