i was wondering if theres a big difference between the nvidia 9400 and 9600? i.e in everyday tasks like opening programs and running coverflow, iphoto and flash vidoes online. Because i currently have the 2.4 unibody macbook and my computer seems to be running slow so i figured maybe an upgrade to the macbook pro might help. also i need it to power the 24inch cinema display. which would be a better choice for me? i'm thinking of getting either the old 2.4ghz macbook pro or the newer 2.53ghz one.