If so, how big was the difference? I'm on a 1.2 ghz G4 iBook right now and I really can't stand how sluggish things can run after being on for a while. Rebooting temporarily fixes it, but when I have iTunes, Adium, a few dashboard widgets, and a browswer w/ a few tabs open, this thing is SLOW. But I thought 768mb ram was a good amount. I'm about ready to plunk down the money, but can someone out there tell me if i'm wasting my time.