it depends. if you want excellent performance, 11.01 does a great job w/DX8a in 3dmark2001, and q3.
there are issues with DX6 games, however. If you don't want that, then you may want to stick with 7.58, or even "drop" all the way back to upper 6's.
IT's still a crapshoot tho, so be sure to test with the games you like to play before settling in and making a decision.