I have an ibook 500 with 20 GB hard drive. I plan to get a 15" powerbook this summer with the 40 GB drive. I saw an ad in Macworld for a 5400 RPM 60 GB drive with a 16 mb buffer. I know that this third drive will be faster than both and is why I'm thinking about buying it. My question is since the rotation speeds, buffers, and bus speed would be the same is there anyway the 40 GB powerbook drive will out perform the 20 GB HD if I put it in the iBook? Thanks.