I got all jazzed-up about this mouse a few weeks ago, and decided to pick one up for my new laptop. One week later, I sold it to a friend.
As far as the mouse is concerned, it's really pretty good -- it tracks great, the buttons feel nice, and the RF receiver fits into the mouse, which can collapse. But it just wasn't for me -- the mouse was too small -- if I were just using it once or twice a week, it'd be okay, but every day for 5 to 8 hours was just too much with such a small design. I could never really find a comfortable position when holding it. After three or four days, I realized that my hand was starting to tense up a bit, and it was becoming sore. I decided not to keep trying to get comfortable with it, and just went back to my old mouse. I think my hand might just be a bit too big for that mouse.
IMO, the scroll-pad is overrated. It's a very neat thing, and at first you are very impressed with it. But over time, the novelty wears thin. The most immediate problem is that it doesn't work as a middle-button -- as a Firefox user, I don't like to do without a middle-button. Then there was the problem with finger position. You kind of have to acclimate yourself to using the scroll-pad -- if you start your finger in the middle and move one direction or the other, you're okay. But if you start from the top of the pad, then scroll down, a lot of times it'll go up for a second, then not scroll at all. I found it sort of frustrating having to be even slightly precise with something I use so much and so quickly. Then, since you can't touch the pad without it scrolling something, you can't really position your hand over it. With a scroll-wheel, if you inadvertently touch the wheel, nothing happens. If you accidentally brush the touch-pad, you're going to scroll somewhere. It makes your hand position a bit more difficult, and I think that's part of why I could never really get comfortable with that mouse.
Oh, and there's this annoying clicking sound -- it's a neat sound, but I would love to be able to turn it off . . .
If you have a smaller hand, this might work for you, but for me, I found the mouse too small, and the touch-pad to be a lot more flash than substance. It is definitely the best-looking mouse around, I just think it's a bit lacking on comfort.