Well, ATi has the overall best feature support, but there are some shortcomings compared to nVidia.
1) Poor T&L performance
2) Lesser support for certain shader functions(register combiners)
3) Poor FSAA
4) Poor 16bit speed and quality(which has already been mentioned but shouldn't be an issue anyway)
5) Improper rendering compared to the native API
6) Extremely poor memory bandwith utilization(HyperZ fails to put them on equal footing with nVidia on this one, even though they have a ~11% edge in bandwith, they lose most bandwith limited benches by roughly that same margin)
Although ATi has the edge, they are definately not a run away winner in this category. Plusses I see for ATi
1) Out of the box color calibration(Recently picked up a new monitor and it took me several hourst straight, and then many fine tweaks to get my nV board to the image I wanted, only takes about half an hour with a Radeon)
2) Video playback- ATi remains best of class
3) Vertex morphing/keyframe interpolation
4) Volumetric textures
5) 16 tap Anisotropic(nV has only eight as of right now)
6) A lot of room for improvement
Clearly the drivers are still in a very poor state looking at the performance relative to the GF2 and V5. With the bandwith available on the 64MB Radeon DDR it should be besting the V5/GF2 in every bandwith limited bench every time, no excpetions. That ignores completely HyperZ which should put the 64MB Radeon on par, if not edging out, the GF2 Pro. If HyperZ isn't another feature like S3's "hardware T&L" and does show up working properly at some point in the future, Radeon owners could see a much larger boost then nV owners had moving from Det2 to Det3. While I wouldn't wager that Radeon owners will ever see that kind of performance(going strictly by ATi's track record involving drivers), we already can tell that nVidia has to be very near the limitations of what is possible with their hardware. Therefore, I would not expect any sort of big performance boost, ever, out of any future drivers for the GF2 while the Radeon it is definately a possibility.