I'm itching to speed up my home movie editing (rendering effects, etc) and DVD encoding. I currently have a 1Ghz iMac G4 with 1.25GB RAM. I'm wondering if I'd see a nice jump in performance from the 1.8Ghz 20" iMac. I actually like the style of my G4 iMac better, but the 20" screen and the G5 make me want to upgrade. It probably takes a good 3-4 hours to encode a 1hr DVD on my G4. Any idea how long it would take a the G5 iMac? Is this a worthy upgrade?