That there are several factors that affect the speed of a hard drive, not just RPM, and the 7200 RPM hard drives that you can buy currently are severely behind more modern drives in other areas.
what ever they are and what ever your oppinion is, there is just ONE fact: My Macbook is a lot faster than before and I am sorry to say that but everybody who runs a core 2 Duo with 4GB Ram and 2.4 GHz must be crazy to break the whole system with a apple 5400rpm drive.
I changed it myself and it works great and faster as before.