The biggest reason I always crave a faster machine is for snappiness. I want programs to open faster, the system to boot faster, webpages to render faster, etc. I care less if it takes 30 seconds or 35 seconds to encode a song in iTunes. I currently own a 12" Rev. D PowerBook, and it's not as snappy as I'd like. Is the MacBook Pro substantially snappier, or is the improvement mostly in things like iTunes and iMovie? Also, is there a snappiness difference between the 1.83ghz and 2ghz models?