Maybe is just paid real good attention to the guy in the campaign hat at Ft. Knox, or maybe it comes from having a plethora of crappy magazines for my Mini-14 growing up, so seating magazines properly is ingrained into my psyche, but I never had a problem with the straight magazine well on the M-16/M-4 series of rifles.
Granted, I was issued some really, really crappy mags when I first got to my unit, but that was fixed with a run to Bass Pro and ten PMAGs.
Honestly, this is the first I've read of the straight magwell thing.
NRA Life Member
Ladyfriend: "I need help with the leaves in the yard"
Me: "Controlled burn?"
LadyFriend: "I forgot my Boy Scout turned into an infantry officer."