Unreal Tournament is a very texture intensive game, causing the 64MB DDR GeForce (with more memory to store textures in) to float to the top of the performance chart while the GeForce 2 GTS is left below the Voodoo4 4500. But if you actually look at the performance numbers, the difference between the fourth place GeForce 2 GTS and the first place 64MB DDR GeForce is 1.5fps in 16-bit color and 4.3 fps in 32-bit color, we're not talking big numbers here at all.
If you're set on running UnrealTournament as fast as possible, you'd be fine with just about any of these cards with the exception of the Viper II whose performance was noticeably lower than the competition.
Because of its larger memory, the 64MB DDR GeForce can store more textures and is thus less susceptible to texture thrashing than even the new GeForce 2 GTS. UnrealTournament is not very fill rate dependent, rather it is more dependent on a fast memory bus on your graphics card, a fast CPU, and a fast system memory bus.
Once again, the performance range between the cards isn't significant to truly draw any major conclusions from the numbers.