How much faster? As all savvy PC users know, the theoretical fill rates can only be achieved by using memory that can support the bandwidth needed. With the added memory clock speed, the theoretical bandwidth is now around 7.36GB/s versus 5.3GB/s of the GeForce2 GTS. That extra bandwidth helps the GeForce2 Ultra improve performance all around especially at high resolutions or when using FSAA.
The 50mhz extra clock speed doesn't improve performance much overall since it's all dependent on the memory. Even with an extra 200 megapixels/s and 400 megatexels/s in fill rate, that doesn't necessarily translate into proportionate performance increases in frame rate. But some things improve like the on-chip T&L unit. More polygons can be used without losing performance.
Other than speed, the GeForce2 Ultra gets 64mb of DDR memory standard. Texture heavy games, high resolutions, and FSAA in high resolutions really make use of this memory. Not alot of games use this much memory, but it's good to know that the memory future proofs the GeForce2 Ultra for the time being.