I've got an itchy finger and am about to buy a MacBook. I have one issue that keeps me from pulling the trigger: I want a large internal drive but the 200 GB model spins at only 4200 rpm (the smaller drives spin at 5400 rpm). As slow as my current machine is, at least its internal drive spins at 7200 rpm. How much of a performance hit will I take if I choose the 200 GB/4200 rpm drive over the 160 GB/5400 rpm? Thanks in advance for your help!