The game itself has no performance issues on my system. It runs smooth.
The Ghosts have weird colored spots in their cammo (I guess thats the tesselation problem). Its not DX11 related, turning DX11 functions off will not solve the problem.
And my 2 GTX580's pump themselves up to 70C in a room temperature of 22C. Now I don't know about other people, but no other console ported game, DX11 textures aded or not, has ever done that to my PC.