I'm planning on getting a new 12" Powerbook within the coming month. However, I still haven't decided on what to do about the hard drive. I have a 120gb internal drive on my desktop that I plan on getting a firewire enclosure for, so the capacity isn't really an issue. What I'm really interested in is what kind of performance difference there is between the 4200 rpm drive and the 5400 rpm drive. Does the 5400 offer a noticable improvement in speed (and is it worth the extra $113?) Also, does the 5400 generate significantly more heat (causing the fan to run more) or drain the battery faster? I'm also strongly considering getting an extra gig of ram (from OWC, not direct from Apple; and if not a gig, at least an extra 512 mb), but would the slower 4200 rpm hard drive make that not as effective? I'm interested to hear the opinions of some powerbook users. Thanks for your help.