I installed a 200GB Seagate Momentus hard drive (7200rpm w/ 16MB cache). I did a clone of my original hard drive onto the 7200rpm HD. I installed the new drive and put the original into an enclosure. I boot up and it's slower. I reboot, and it boots quicker but not as fast as before. Some apps are quicker and others are slower. There is a minor vibration on the left side below the keyboard. But I expected some vibration. What I didn't expect was longer boot times. I do not recommend the upgrade. .