So, you have a half dozen of each?
Just a turn of phrase, i have way more than that. I could just about fund a 3 week trip to germany if I chose to sell at market prices now.
They all work. For some reason my wifes AR prefers the pmags over the used surplus. Havent tried any of the new alloy magazines in her rifle yet. My 5.56 likes them all new alloy, stainless, used alloy and pmags. It aint picky. My 300 blackout really dislikes my old surplus alloy magazines.
FYI magpul says life expectancy of a pmag is 60k rounds. But their have been reports of pmags with 100 to 120k through still going strong. They had an industry rep respond to a thread on arfcom.