Yep it will give you good frame rates Jet. BUt have a look through the forums anyway. There is some good info on that card somewhere here.
I seem to recall that the 9800 pro 256 MB card was not as fast as the 128 mb one though. Not sure why (most of this stuff goes over my head), but Skuzzy has a reply referencing that around here somewhere.
cheers,
RTR