I just replaced my 1.33GHz 17" G4 Powerbook with a brand new 17" HD SR MBP. Previously, the G4 PowerBook was left on continuously at my work for four years straight. I was running a mail server and web server on the G4 so it had to remain on, albeit with the screen saver running. The battery now reports that it has 75% of the original charge capacity using Coconut Battery. Not bad for four years continuous use with next to no battery "maintainence". The only thing I noticed is that the screen is slightly less bright than my new MBP, even on full brightness. Given that it has been running the RSS screensaver for the better part of that four years I think this is pretty good going. For all those people worried that their non-LED MBP may not get as much life as the LED models, please keep my experience in mind. If your new 17" MBP is still completely working in four years I think you would be very happy. Most of you guys seem to get a new mac every year or so anyway. My old G4 PowerBook is now being shipped to my dad as it will serve him very well for many more years to come.