"Now if they'd just make the AR in 6.8 and give the bolt only two big sloppy locking lugs (not the tight gear/tooth setup)"
Caliber aside, that's just one of the things that bother me about the AR15 design. I hear too many stories about cracked bolt lugs, broken bolts, worn cam pins, weak extractors etc.
The extension for the recoil spring is a lower receiver weak point. The feed angle from magazine to chamber is very steep. The space over the bolt and bolt carrier is a big design oversight. It is big enough for a cartridge to jump into and can enable a particularly hard to clear stoppage.
The ability to assemble and fire the rifle minus the cam pin is potentially dangerous. The tiny, removable, cotter pin that holds the firing pin and bolt carrier together, is a potential loss problem in the field.
The M16works fairly well in spite of it's design. Its ergonomics are great.
However, I feel that the M1 is a very well thought out design. I can't find any serious design faults with it.
I own a Colt AR15 Govt Model. It works pretty good for me but I just have those nagging feelings about it and I don't trust it like I trust a Garand.
Will the M16 be fondly remembered? I suppose some will remember it that way. I also know some military people who hate it.
On the other hand, from almost everything I have read, praise of the M1 by a majority of soldiers, almost amounted to affection for their rifle.