I saw one of these as a clearance item at MicroCenter yesterday, so I picked one up to try it out. In the tiny bit of time I’ve used it so far, the only annoyance (and a minor one at that) is turning the mouse on and off. I find it challenging to move the slider on the bottom of the mouse without clicking the mouse body a few times. I like the little trackball on the top for 360 degree scrolling (though I don’t find myself scrolling sideways much with a 24″ monitor). I haven’t played with the configuration tool much yet, but it appears to give you a wide variety of ways to customize the mouse’s behavior. We’ll see how the battery life is.