My last laptop was a 17" 2.4 GHz Macbook Pro which just died when it fell out of a bag I was putting on a shelf. I just bought a new Unibody 17" with the same amount of RAM (4GB) and it seems noticeably less responsive to me. The new unibody has a 5400RPM HD compared to my old one which had a 7200RPM HD. Will this make that big of a difference in the responsiveness of the computer? If it's that bad I might just go out and buy a SSD. The responsiveness seems slower than my new Mac Mini.