I'm not 100% sure of this... but it seems my Momentus XT runs a hell of a lot better on my sister's 06/07 2.16ghz White MB than it did on my MBP. It starts up and loads OSX in the same time as my SSD on my MBP. It's a lot smoother, starts up faster and is less vibrate-y. Though I think this does have in part to do with that it is a second faster on button press to actually "turn on" from a black "off" screen to the grey lit up screen. Anyone else put an Momentus XT in a white Macbook?