Nice to load, it's faster than a usual to load. However, feeding problems are rife, there is a problem every time, all 4 mags, with picking-up rounds 25 to 20. Thereafter, relatively smooth. So, now I'm forced to not load full capacity, stopping at 20 rounds. A further very annoying problem with three of the four I have, is to get them into the magazine well, and to get them to catch. Truly a frustrating wrestling match. I only hope it gets better with further use, friction and wear being what they are. They are well made.
I have to add I have so far, I have only used them in temperatures ranging from 2°C to 7°C. Maybe they function better at higher temperatures. TBD.