To quote Subject Matter Expert Sean M, who has likely thrown away more AR mags than I've bought:
I'll take his word on the latter, because I only buy the first three. Well, actually, the first two; I've kinda cooled off on the HundK mags. All my GI mags, I think, have Magpul followers in them, except for the newer Brownells ones I got.GI mags break. PMags break. H&K Mags break. The other cheapo knock off hunk of shit mags break.