XM8 (ADV) or AK-47 (CAMO)

I'd like to know which of these two are better.

XM8 (ADV) - (Has better accuracy,scope, and less recoil. Loss of power but if good enough with shots and handled by the right player it in my opinion, along with a few in game is a over all better gun)

AK47 (CAMO) - (Has more power, a tad bit less accuracy but a high recoil, good for close encounters basically that's all, good if tapped right)

Also to clarify a statement a friend of mine made please tell me this (even tho i've checked on site on guns such as M4A1 (NORMAL) and (ADV)|) ADV makes guns better correct? Not only dose it usually add +5 bullets but it increases the accuracy sometimes and lessens the recoil from what i've seen on site and IN-GAME. Please clarify this statement. Also the fact that AK47 (CAMO) is not a (ADV) gun.

Thanks.