I wanna boost my 2.4 C2D Macbook Pro, but I can't decide which way to go.. I have enough money for either installing 8GB RAM (I have 4 now) into it, or changing stock 160GB 5400RPM HDD for a 320GB 7200RPM one. Which will be more useful? I have enough hdd space on external drives, so I'm upgrading for speed only. I do film editing in FCP2 and some Photoshop and some web-browsing of course.