Aliens vs Predator uses many DirectX 11 features for cards that can support them. This includes tessellation, like the other DX11 games tested, and other lighting and anti-aliasing effects. With everything maxed out, but GPUs are unplayable. The 6870 is almost playable, but there were a couple of times in the timedemo when the framerate dropped to the low 20's which translated into slight stuttering. The GTX 560 was further off the playability mark by being over 25% slower on average.
Disabling MSAA and makes AvP playable again on both cards, with the GTX 560 back to competitiveness with the 6870. It's still a little behind, but both GPUs essentially perform the same with these settings. MSAA seems to have a bigger performance penalty with the GTX 560 in AvP.
S.T.A.L.K.E.R. Call of Pripyat uses the XRAY 1.6 game engine which offers a wide range of DirectX support, version 8 through 11. It does support tessellation and its implementation results in a lot of realistic looking buildings and scenery. And to help create a scary ambiance, lots of dynamic lighting effects are used. Maxing out all of the settings, both the 6870 and GTX 560 are easily playable with minimum framerates on both cards around 40fps. The GTX 560 came out ahead by 9%.