Yes the aa12 and manual action shotguns are still rather poor weapons when compared to the rest. The fact that the pumps start out requiring 4 pellets minimum to kill is just silly. They should have buffed the pumps to take 3 pellets to kill up close when unlevled and take 2 inside thier max damage range when damage is equipped.
The aa12 is a mess. It requires just as many shots to kill as an smg. The aa12 takes 2 shots up close and up to 5-6 shots at the end of its range. At 400 rpm that gives the aa12 very bad kill times. That gives it bad kill times inside of the already shortest range of any shotgun in mw3.
To tell you the truth I don't think the acr and pp90 are that bad. The acr has bad kill times up close so any smg or faster killing AR will crap all over it in cqc. The acr shines at long range but some gun had to. The acr at least has a weakness that is somewhat easy to exploit.
The pp90 is the reverse of the acr. It is devisdating in cqc but because of its 6 bullet kill and not great recoil it loses its effectiveness rather quickly and is easy to beat at mid and long range.
The type 95 and mp7 on the other hand are over powered. Both have spectacular performance at any range. The mp7 is the worst because at least you need to be somewhat accurate with the type 95 because its a burst gun. But the mp7 can just start firing immidiately and adjust aim after.