I haven't benchmarked it, but it seems to be a lot faster than 6.26 to my eye in Need For Speed: PU (5). You can tell the difference by racing a fast car (eg. GT3) on the Scharzland (I hope it's spelled right -- it's the LONG, LONG forest track), which is the most detailed and bloated track in the game. It turns the game's FPS into Powerpoint! However, I saw a huge difference when racing this track. It is much nicer to play now. You can't tell much difference on the other tracks, which look awesome already with the old drivers.
I have the GF2 GTS 32MB.
Athlon 700MHZ Classic, 751 chipset
128MB RAM PC100.