I have a mix of Pmags, MFT, and Elite Tactical Systems mags.

They're all good. I use the clear Elite Tactical Systems mags exclusively with .300 Blackout. It just helps to use one type exclusively for .300 Blackout to prevent safety issues if you have or ever intend to venture into .300 Blackout territory.

Of the Pmags and MFT mags it's whatever I can get for the best price really. If I had to choose though the MFT mags shave some weight and bulk without sacrificing any strength and so they are my preferred choice. A few days ago PSA had the MFT mags for $6.99 so I added a few more at that price- a true no-brainer.