Haven't run into any areas that drop below 60 fps yet even at Ultra settings with the exception of loading slowdown. This IS an AMD game after all.
With vsync off my framerate is over 100 most of the time. Though you're right about the Ultra shadows not looking any different than very high.
Core i5 2500K @ 4.8 GHz || 16 GBs 1600 MHz DDR3 || Saphire Radeon HD 7970 || Dual 128 GB SSDs