There is a dedicated server client for Black Ops 2, Modern Warfare 3, and World at War. It's called Plutonium. Over the past week, there have been about 850 players consistently playing Bo2.

There are tutorials to download it online, but I'll also give you some main details.
1. Click the link below
2. Download Plutonium (follow the download on that page)
3. Launch the Game
4. Hit the " ` " key to open console and type "unlockall" (unless you wanna start on level 1)
5. Create your custom classes
6. Browse the servers and play!

The main reason I'm sharing this is for the ability to play any modes besides Team Deathmatch, which is all that Bo2 is now. With Plutonium, there were at least 4 open Search and Destroy servers to play on. I didn't have to mess with my game settings either.

Hope to see you guys in game!

https://plutonium.pw/

*Edit* I will also most likely be playing MW3