I've only played 3 so far but so far I like them. Creek is a great map for snipers. All you could hear on my stereo was the head shot sound & it never got annoying

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Chinatown is also another good level & tons of sports to hide & run to for cover. Also lots of twists & turns so its no just straight forward shooting.
Broadcast is my favourite so far. Reminds me so much of Counter Strike & thats a good thing. Love the fact that helicopters & airstrikes can't kill you because its inside a building.
For future advancments they should bring in a hostage playlist where you have terrorists & anti-terrorist teams ala CS. New playlists would also be cool but for the moment I'm having fun with the new maps.