Here's my experience with SBMM, in theory it sounds great, in reality, it doesn't work. If you're good enough you will consistantly get put in lobbies with 4+ party teams, and 2 things will happen. You will get stomped in which case half your team quits. OR you stomp the other team and they quit.
I've never experienced so much rage quitting by other players in any game as I have with this. (Aside from maybe MW3's 2v2 playlist )
People will quit when the game is too lobsided, so Treyarch's focus shouldn't be on skill-based matchmaking, but on creating teams that are equal skill-wise. I think people will be less likely to quit if the games are closer.