Bah, mid range the AK is good for 2-3 shot bursts, at long range 1-2 shot bursts and close up you just better pray there isn't more than one enemy because the full recoil on that bestie is such that you can empty a whole clip and not hit a barn door.
With the busrt fireing the thing you got to control is don't go for your second burst till the crosshairs return to normal otherwise very quickly you'll find your shots out of control.
The M4 is pretty good all round but its annoying to get killed after hitting your foe with x bullets and know that if you were using an AK they would be dead not you.. the saving grace of the M4 is the silencer (sound plays a big part in CS for me) and its much more controllable if you get caught out close up and have to go full auto.