i thought the AK was one of my fav alternate weps from COD4. i used m16 most, but the AK was always fun for semi-close or med range fights. this time around, its much less used (mostly due to such a late unlock). but ur right, its fairly buff. though, i would argue just a tad bit less effective than the TAR.
TAR > AK (rate of fire)
TAR > AK (iron sights)
AK > TAR (accuracy)
the raffica is alright, but remember its a 3 shot burst, ala exactly the same as a famas/m16. thats OK if ur confident the connection is stable (shaa right) and assuming u hit all 3 bursts at the same time. i guess if u go akimbo, u can hope u hit 3 shots with 2 guns, but i just dont like it. its a good wep for med range takedowns, but i dont like it for up-close. id much rather have the glock or pp2000 with a slightly lower dmg per bullet but a much greater rate of fire.
if u want pistols, i would even suggest the M9 akimbo (not much recoil).