I know some have had issues with Taran extensions popping off, but mine have been solid. They've seen a ton of use in USPSA particularly, and many biathlons where they took some hard hits from low crawls and obstacles. They're far more dirt/dust resistant than ETS or Magpul mags, and far more durable.
I also have an OEM 24 which I've started using for biathlons, but only as a replacement for my 21rd PMAGS. I bought my Taran extensions many years ago when TLG first wrote a post about them. Beyond replacing the stock springs they've held up great.
I don't have any complaints the OEM24 other than its a bit long to leave in the gun while running through an obstacle course, and the floorplate isn't super comfortable for carry. I prefer the OEM+2 or Taran+4 for carry. The Taran extensions have a great rounded profile which doesn't print or poke me the wrong way.