When we played at 1920x1200 on ultimate, the Radeon HD 7970 GHz Edition sustained 53fps and that figure increased 47% when we disabled TressFX. Most gamers probably won't be able to justify that kind of performance hit. And it's worth noting that TressFX isn't the reason for Nvidia's poor showing -- that seems largely due to depth of field (DOF), which we discovered after a lengthy session of trial and error.
The Nvidia cards only performed as expected when we used the high quality preset, and the changes when shifting down from ultra to high include texture quality, level of detail, depth of field and SSAO. After testing each item, we found that changing DOF to normal while leaving everything else on ultra produced a 48% boost from 54fps to 80fps -- and that's with TressFX enabled as it is by default on ultra quality.
If we set the DOF level to high while on the ultra preset, the GTX 680 gave 47fps at 1920x1200, which is just 2fps less than the HD 7970 -- far more practical results. Folks playing with an Nvidia card should definitely watch for a driver update that fixes this issue. Of note, texture quality, level of detail, SSAO and texture filtering had virtually no impact on performance while tessellation accounted for only 4fps.