Haha, yea my wife's been telling me the same thing
I don't agree on the SMG comment at all, as there's not a single map I can think of that you can't dominate on with either the Spitfire, Cordite, Saug or MX9 (had mixed results with the other one, the Demascus ... or whatever the standard name was for it again). Hell, it's even easy to annoy the crap outta people with the shotguns on any map.
You do need to adjust your play style to suit the gun you use for sure, but I tend to run SMG most of the time. The spitfire is basically a god gun, that deletes people at close range, and has such as predictable recoil, you hit shots from across the map if you burst it. I use my sniper rifles as secondaries to the Spitfire with Overkill perk, as the spitty needs little attachments to make it epic.
Same applies to the others, the Spitfire's just my current go-to if I want to be guaranteed a good game. If I want to **** people off, then I run the akimbo Saug, particularly on maps like seaside, where Saugs will consistently get me 30+ kills and less than 10 deaths.