Hello- I am wondering if I should get the BTO upgrade to the 5400 RPM drive? I will be using an external glyph 7200 RPM firewire drive for audio. How much of an improvement will I notice (is it worth $113)? Also, if I get a BTO from the school store, I do not get free Apple care with their spring promotion, so I'd only get the upgrade if it was going to make a huge difference. I've got a stock 12" PB on hold, but can easily cancel my order. THANKS!