I'm trying to decide between a new Powerbook 1.67 Ghz, and the previous generation model the 1.5 Ghz. The speed upgrade dosen't matter to me, and my only concern is the hard drive speed. The 1.5 has a 4200 rpm internal hard drive, while the 1.67 has a 5400 rpm internal drive. I'll be using it mainly for internet, office tasks, and occasionally recording (my main studio computer is a G5). And I'll obviously also be using an external firewire drive for all audio. Will the 4200 rpm drive give me problems? If it's only running the OS and the application does it matter? The 1.5 model is about $450 less that's why I'm considering it. Thanks.