MSMC: Recoil is increased to the point where it's harder to kill people from long range, but the SMG function of it remains the same. I feel that Suppressor is a bad choice now however, as that one less bullet is precious at range.
PDW: For some reason it seems like the recoil is more manageable. Now I use this over the MSMC O_o
M8A1: Not very different, it's a 4 shot burst so not a big deal that the 3 burst kill range is reduced. You just have to be more accurate. Now it's more viable to use a suppressor on it. Not to mention there's less idle sway on the ARs now, improving its counter sniping ability.
R870: Right where I like it. It's still very powerful, but you don't get any ridiculous one hit kills. They balanced it as best as they could in comparison to the original stat design of the weapon (I'd personally give shotguns really tight crosshairs with a slightly shorter range so it isn't easy mode, but that's just me).
Haven't tried anything else. I bet the M27 is more ACR-like now though.
GT: OhBlivEeUn BO2 lag compensation gave me an aneurism.
It's disappointing I won't score amazing 40ft OSKs anymore. But I'm equally relieved it won't happen to me again. The other guns honestly feel the same killing and being killed, my friend who isn't good at all is going positive with 20kills using the M8A1.
I was learning to use the other shotties and the 870 really seems to be the only thing with a noticeable difference.
This is all IMO if course
Get it right, do it nice. If you make a mistake, you're gonna pay for it twice. If you need it... got to have it. Get yourself a shotgun and bring it back home