polymer vs metal ar mags?

i use both and the ones in the pic work good but which one do you think is best? what would you stock for SHTF? promag is a joke. they are made from tupperware and not polymer clearly because the feed lips spread like a mf if you put >20 rds

i use both and the ones in the pic work good but which one do you think is best? what would you stock for SHTF? promag is a joke. they are made from tupperware and not polymer clearly because the feed lips spread like a mf if you put >20 rds