The Geforce 6800 DDL holds its promises

XLR8yourmac has published comparative benchmarks of a Dual 2.5 GHz with a 6800 against a Dual 2GHz with a 9800 Pro.
To be fair, we've only looked at the tests in the highest resolutions, where the GPU chokes before the CPU does: in Quake 3, the 6800 is 50% faster than the Radeon 9800 pro.
Barefeats also published some tests: The 6800 is 15% faster at 1280*1024 in UT 2004. It would probably fare much better at 1920*1200.