At least from what I've read and experienced, enabling TressFX pretty much drops your performance by 20 FPS on nVidia hardware. Kepler wasn't really built for DirectCompute, which is what TressFX uses. Honestly, you'd probably have a better experience with a 7970 Ghz.
Also, keep in mind that the Ultra preset uses FXAA instead of SSAA. At least from what I've noticed from switching between the two, FXAA usually gives me between 10-20 FPS more than using 2x SSAA.
I'm wondering if we'll get some good driver optimization from nVidia. nVidia's website doesn't list Tomb Raider anywhere on their driver page, which isn't common as they usually will tweak the drivers to offer greater performance prior to a game's release.
Don your tin foil hats folks, because maybe that's why Square-Enix wouldn't release the PC version for review! AMD didn't want nVidia to get their hands on a copy to perform optimizations in their drivers to make the cards look worse at time of review. The conspiracy!