Really BIG Magazines

A favorite of video game players, but here in meat space I usually avoid the extra big magazines due to reliability worries.

Smarter peeps than me have gone over this.

I am such a fuddy duddy I still still look askance to double stack magazine for the same reason, but regular Glock factory double stack have run like a house afire for 3 decades, so the fuddi-duddiness is on me.

But... are their any supersized  60 rounder magazines on the market that actually ARE reliable?  Not "Well, my drum mag has never failed ME." But never failed anyone.  And never failed anyone enough that they are accepted institutionally.  The last bastion tail-end acceptance group whose resistance to change is always achieved last.  

I mean, Magpul is highly regarded.  Maybe their drum magazine gets it right.  You tell me.

And those fatty box magazines intrigued me when they first came out years ago, and I was waiting patiently to see if they ended up with a decent history.