I'm thinking about upgrading my MBP CD to the newest MBP C2D 2.2GHz. I'm aware that the processor will be upgraded and utilizing the new Santa Rosa chipset, however how about the graphics card? Is there a major jump in performance from the X1600? Is 128MB sufficient? I can't afford to go with the 2.4GHz, but really is it worth the extra $500 for it?