i can tell that they apps run a lot faster at this speed. all my programs install a lot quicker too. i installed office xp last night and it was done in probaly 3 minutes. i have a 1.8 at work, and it's definitely not as fast as my new computer.
UPDATE: i ran 3dmark2001 and here are some of my results:
6800 with whatever driver came with the disk
6994 with detonator 4 version 27.50