Having played both, I'd say you can't really compare the two.
Theatre of war looks pretty, but (in my opinion) it is a real time stragey game, where the emphasis is on deploying your resources in a way that will beat the programmed puzzle in that scenario. It's also hampered by the lack of essential elemnets such as the deployment of smoke and the ability to enter buildings.
CMSF is a wargame, where the use of sound strategy and tactics is required. Apples and Pears stuff. Like people have said, download the demo and see for yourself.