30 round mags have more material to grip for reloads so there's that.
ETA 10 round mags are a pain in the ass especially for AKs. I have exactly 1 10 round mag for 762 545 and 556. I might, MIGHT use them if I want to site a rifle off a sandbag or something.
Nope you are wrong I was told it's a training thing and I'm an ass hole for saying otherwise