I think this is what Dave means (correct me if I'm wrong):
In a heavy scene that is fillrate intensive, the V5 and GTS will be about similar, maybe with a slight edge to the nVidia card, say 70 vs 75 fps. This is in cases that are fillrate intensive, and the fillrate is the bottleneck (restraining factor) on both cards.
In a less heavy scene, which is not fillrate intensive, then the V5 can go as fast as the cpu provides the transform data, which becomes the limiting factor for the V5, and the V5 will have fillrate to spare. In these cases, the cpu might pump out enough transform data for 90fps, and the V5 will draw the 90 fps, with fillrate still to spare.
Meanwhile, in such a "less heavy scene", the GTS will not be limited by the cpu, because it has the spiffy T&L engine which will do the transform operations, and this will allow it to achieve, say, 150fps. In fact, the limiting factor might be the fillrate, since the T&L engine can pump out more frames than the fillrate is able to fill, so the T&L engine allows the nVidia card to max out it's fillrate in a simple scene at 150fps in a non-heavy scene, and then dropping to 75fps in a heavier scene (more fill rate intensive scene).
The end result is that the V5 will fluctuate between 70-90fps (depending on the scene) and the GTS will fluctuate between 75-150fps (depending on the scene. Supposedly, the more consistent framerate on the V5 will be a boon to gamers.
Folks, I'm a V3 owner and a 3dfx fan in general, next upgrade for me will be Fear since the V3 is running everything fine for me for the next year or so. Nevertheless, as a gamer I do not mind if my framerate spikes upwards during simple scenes. A spike upwards is never a problem for me (but a spike downward certainly is). Then again, I play mainly UT, and not Q3A. Now, it is known that Carmack's engine and Carmack's physics *vary* depending on your framerate, for example, the height/distance that you can jump in Q3A (or Q2, or Q1, for that matter) varies depending on your framerate. That being the case, if you play a Carmack engine game, then yes, I suppose having a consistent framerate would be a boon, since it would give you consistent (dependable) gameplay. In the UT engine, however, physics is not dependent on framerate, so I do not mind upward spikes.
Of course, if someone pops in a 2ghz cpu, then the V5 is no longer limited by the cpu; the V5 can produce, say 145 fps in a simple scene, maxing out its fillrate, and you would thus get wild variations in framerate on the V5. The moral of the story is to not buy a 2ghz cpu if you have a V5 and play Q3A.