Shotguns as secondary was really no big deal to me. I play mostly snd and i still use the usp (or as my friends and i call it, the ppsh) most of the time. All you have to do is not go hurp durping around corners and you'll be fine. It wont bother me having them as primarys anyways. I used them in cod4 like an addict, the only difference it'll make in mw3 (assuming i buy it) will be i wont have to listen to kids bitch about using my secondary.
I do hate there maps as well. I can't put my finger on it when somebody asks why, but there style just sticks out from IW for me. It's not a graphics thing, it's just how the game...is. idk it's weird. but w/e it is...i see it in the previews.