Maintainance wise, perhaps. I think the M4 is more accurate with less recoil than the AK, especially when not stationary, if such things matter to you, though.
yes, the M-16 family is probrably more accurate - but what I meant was that my first reaction to his post was that he was wrong, that the AR-15 is a great weapon. but, the AK family is great, too.
the AK is tougher, and is still pretty light. the AR-15 is like a pistol, in terms of weight, is very comfotable to use, has great killing power. its just a little more fragile.