The Ultimate Trackball! The best trackball ever made has just gotten better. Designed for PCs and Mac's, the new Expert Mouse employs Kensington's Diamond Eye optical technology for smooth, precise cursor movement. Surrounding the ball, we have a brand new implementation of our award winning Scroll Ring that puts scrolling right at your fingertips. More comfortable than ever, the Expert Mouse even comes with a soft new wrist rest-right in the box! You get all of these great new features along with the same, large ball, exceptional control, and ease-of-use that has set the industry standard for more than 15 years.
Its hard to provide a fair review when the first 4 hours of ownership are spent uselessly trying to get the software from the manufacturer to work. http://www.kensington.com/kensington/us/us/s/1517/trackballworks%e2%84%a2-software-download.aspx is where I end up after following the included instructions. The downloaded windows software (after a lot of digging) does not run on 64-bit computers. There was a 64bit BETA software back in 2010 but that does not work either. I have tried on Windows 7 64bit, Windows 8 64bit, and Windows 8 32bit.
The downloaded installation package is unsigned so it won't work on a business Windows 7 32bit computer because that won't let me do unsigned drivers.
I have sent Kensington an email tonight. Hopefully I hear back from them soon so I can update this review.
What's great about it: Big trackball - large 4 buttons
What's not so great: Without the trackballworks software this is not very useful