I'm using my new C2D 2.16/2g RAM Macbook and love it. The best part is the sheer speed of the interface, everything I do is instantaneous. Ever effect is instant. I love tiger's performance. Does anyone have any ideas about how the performance of the UI will be on Leopard? A possible slowdown because of increased system reqs? A bump do to taking advantage of dual cores and 64 bit? Will 2gigs of RAM be equivalent, or not so? Thanks for the input.