bill - 4:30 am on Apr 11, 2012 (gmt 0)
I tried playing around with some of the trackballs in the store, but I couldn't get used to them in a short time. The thumb-ball models were particularly disorienting. I guess if I had given them more time I might have got used to it. I found myself trying to move the entire trackball unit like a mouse.
I went with the newer Logitech Performance mouse that coopster linked to. Although I've read the different reviews of this model I haven't run into many major issues. The USB plug lets you use the mouse just like a corded mouse while charging, so I can see why they got rid of the docking station. There's no interruption of your workflow that way.