I've been using 5 of the 22 round 9mm magazines for general use. A few would only load 21 and thank to the clear bodies I noticed the rounds were not stacking properly in the magazine body occasionally. Now that the springs are worn in I haven't had that issue. Yes, the magazines bodies are lighter, but for a 140mm magazine, they are significantly cheaper than anything 17 rounds with an add on extension. I also use them to train new shooters. Allowing them to visualize what is going on inside the magazine is beneficial imo. Overall I cannot complain. They have worked well and mine mostly get dropped onto concrete as that is where I practice mostly.