Recently in Ghost, I have been moving away from the Assult rifle and using some different weapon classes. The SMGs are surprisingly effective in this game, and don't require quickdraw or stalker like the AR, MR, and LMG builds usually do. The weapons are a lot more mobile as well and allow quicker traversal of the map. I have been playing the K7 SMG a lot lately and I find it a lot of fun with it's built in silencer, however, I was having difficulty with it on lager range maps because it has moderate recoil and a 7 shot kill at long range. So, I found a class that works fairly well with it.
Primary: K7 SMG
Attachments: Grip, Extended Mags
Secondary Weapon: VKS Sniper rifle
Attachment: Variable Zoom
Perks: Overkill, Reflex, Ready Up, Marathon, Focus
The K7 is a solid weapon and the built in silencer is nice for keeping off the minimap while firing. Adding the grip and focus to the class make the weapon usable out to midrange. The extended clip gives me an extra 16 bullets between reloads for fighting more than one opponent, it also gives me an extra 48 rounds of ammo per life. Ready Up and Marathon pair nicely with an SMG build and allow me to stay very mobile. I didn't go for off the grid with the class because I am not normally in one place long enough for a satcom to pinpoint me. The real problem with this weapon is outside of 25 meters you cannot compete. That is where Overkill comes in.
I have seen a lot of sniper builds in COD history that use a SMG or shotgun as a secondary via overkill to avoid having to fight with only a pistol. I decided to kind of invert it here and build a SMG class with a sniper for back up. If I see somebody too far away for the K7, I use reflex to jump onto the sniper rifle and pop them off at long range. The VKS shoots reasonably quick with semiauto fire and it has the built in silencer. Alternatively, if my team gets into trouble, I can jump on the sniper, pops a few shots of cover fire then get out of there. It's been a rather effective class and a lot of fun to play.