I'm on the verge of buying a new MBP (the 15" 2.4 Ghz, and by "on the verge" I mean I'm going to click "proceed to checkout" as soon as I resolve this question), but am hung up on what to do about the hard drive. I'm very tempted to upgrade to the 7200 RPM drive, but I'm a little worried about how that will affect battery life, heat, and noise. Can anyone offer any advice on the decision?