I'm thinking about purchasing an iBook (Dual USB)...the new one. But I'm concerned that it will not run OSX very well. Can someone give me some input/feedback on this? I can't afford a G4 Powerbook so I'd have to go with the iBook. What about this whole 66mhz system bus thing? What other things should I know about and/or think about? How different is a G3 500mhz from a 400mhz G4? What is the downside? What is the upside, or is their one?