Running the Covert Sneakers and Ghost is great fun as most players chase red dots and just listen for footsteps, so you can now run right up behind people. I've already done a couple of executions.
I absolutely hate a few maps. Rust, Estate and Wasteland can do one. Invasion is getting on my tits as well as players tend to camp in the Embassy.
In the OG MW2 I wasn't a fan of Underpass or Rundown at all but I actually really like both of them in this game.