I wish I still had my r300, I guess I could try Unwinders AD for 3dmark2001SE with my R200 and see if those optimisations are still there and just how much they affect performance
Well I can confirm that ATI has had optimizations for the r300 throughout the whole 3.x series and atleast up to the 4.3s as is shown by the fact that nature scores have changed negligably in this period.
My loss in frame rate in nature as I said is comparable to the level of optimization Nvidia is currently using on the benchmark. TBH if I was Nvidia I'd have left the aggressive optimizations in, if your going to cheat why not go the full distance and go for the win :P
EDIT: It would be interesting to see results from an r200, I expect there are still optimizations in the latest drivers, what would be most interesting is to use 3d analyse on old ati and nvidia drivers using the gf3/gf4 and r8500 to find who introduced detection of 3d mark 2001 first :P