Check out this video to see a DX11 tessellation on/off comparison featuring Tom Clancy's H.A.W.X. 2 on an Nvidia GeForce graphics card.
Do you notice the detailed terrain and environments when tessellation is turned on?
Pretty cool, eh?
Note: For a limited time, you can receive Tom Clancy's H.A.W.X. 2 free when purchasing a qualifying Nvidia GeForce graphics card.
Additional details can be found here.
Full H.A.W.X. 2 trailer: