I have a 600MHz iBook with 640Mb of RAM, but only 8Mb of video RAM (as I recall). I am running OS 10.1.5 (never upgraded to 'Jaguar'), but am definitely going to upgrade to 'Panther'. What kind of performance boosts should I expect? Is 'Quartz' going to do me any good? My computer seems to be slow at refreshing/resizing windows, etc.