I've had a number of .223 Gen I Americans set up for both AICS and AR mags. The last AR mag version (a Ranch model) was the only one I shot much; it was my dedicated coyote rifle for a few years and worked great with MFT mags, which was all I tried. Feeding and overall function was perfect. I just prefer AICS mags.
The AICS-magwell-equipped one worked just fine with Magpul, Accurate Mag and Ruger-marked mags. But as stated above, removing the action from the stock with that set-up was a tiresome PITA right from the get-go and didn't get any easier to tolerate as time passed.
I also had a .22-250 Gen I American Predator mounted in an MDT Field Stock. Loved that gun/stock combination, very comfortable and accurate to shoot, not too heavy, but again...absolutely hated the nonsense involved with removing/replacing the barreled action into the stock.
Overall, the best version in many ways is the original Ruger rotary mag one; it's very comfortable to hold and carry with no bulbous magazine sticking out at the balance point. I had one of those, an older .223 one that was not capable of being "upgraded" to take an AR mag. I liked the gun itself, but the amazingly flimsy OEM magazine cracked one extremely cold winter day when dropped, fully loaded, onto ice from a height of maybe three feet.
Could Ruger make those mags out of metal, or at least a quality plastic that stands up to extreme cold? I'm sure they could but won't. Could they manage to figure out how to mount an American into their own stock without using that idiotic front-of-the-trigger-guard screw location? Not without redesigning the whole receiver...pretty sure they won't do that. Will I ever buy another American? Pretty sure not.
The post above that mentions how the Magpul stock and magwell has managed to overcome the awkward disassembly thing by using two separate screws is interesting, but I don't like the Magpul stock in terms of either comfort or appearance, so I doubt I'll pursue that. Would love to hear more, though.