Not sure if this is a hardware or sample question: Is a 1.2 GHz motherboard fast enough for this piano? (Yes I'm on a budget and thinking about one of the low-end computers at Fryes. Really can't make the big investment in the latest and greatest computer, but I want to try out this piano and some others that need a better cpu than what I have.)
The demo is a good idea. Try to create a small piece of music utilizing the demos two full octaves and play it with your sequencer/notation program. But, if you use Kontakt 2, I don't think you should set your hopes too high. TBO/K2 is eating a substantial part of my P4 3.2 GHz power. Another possible bottleneck is your harddisk. You will need a fast - min. 7200 RPM - harddisk dedicated to the samples.