Right now I have a 5400 RPM 250GB that comes with the 15" MBP. I am an amateur photographer and take a lot of RAW pictures. So I am running out of space. I am going to upgrade to the 320GB Western digital, the only question is 5400 or 7200 RPM. I use Apple Aperture and Photoshop CS3. Will I see an improvement in speed on either program? Will this help write my large RAW files faster from the camera?