Usually those uber settings just tank your frame-rate for barely any appreciable difference in quality. In a lot games these days going from around medium to high to ultra the differences are pretty much negligible.
I just hope they've upped their texture quality, this megatexture gimmick was hyped but all it seems to deliver is barely adequate textures coupled with pop-in. Doom 3 had crap textures long before megatexture stumbled onto the scene drunk promising the world, but its almost forgiveable given the gpu's back then had much less ram (around 512mb for the high end) plus the fact that id were doing a lot of other effects that also ate up vram.
For rage id hyped the fact it was streaming 30+ gigs of textures, they just forgot to tell anyone they looked like they had been compressed, **** on, then stretched to make them super blurry.