I have a Powerbook G4 with 1,5 Gb RAM. How well will it be able to handle Aperture 1.5??? I have run Canons "Digital Photo Professional" on both my stationary PC and the Powerbook, and it seems that the Powerbook struggles to keep up speedwise. Anyone who have tried the hardware, and will I need to buy a new mac to run Aperture in a sensible way??