HI,
Actually, there are many advantages to 64 bit processing. It has to do with how the computer represents large numbers and how many memory accesses are required to read and store numbers. Besides being able to address a much large memory space, you will well see big differences with any program that uses computationally intense methods. A good example is Photoshop when it is rendering complex image transformations.
That said, I'm using 32 bit Vista because of the lack of 64 bit drivers and current programs that really use 64 bit processing. But that will change and 64 bit processing will become the norm. The same thing happened when we went form 16 bits to 32.
Sparky