Evoluent VerticalMouse 4, Right Handed, Laser, Wireless

The tracking is very poor, on a desk or a mouse-mat. My current mouse (Logitech) tracks flawlessly, as do a few other mice I have around. It works okay on a piece of paper, but I don't want to be restricted by that; I prefer not using a mouse-mat at all.The build quality is also not quite up there with my Logitech mouse, which was half the price. I appreciate that this is a niche product, and commands a higher price. However, the power switch was fiddly and did not engage properly without some back-and-forth, and my (brief) impression was of a lower level of robustness than I hoped for.Sadly, I am returning mine.

Having used two different good quality 'ergonomic' mice with varying degrees of success and comfort, I tried the wired series 3 Evoluent mouse which I found to be very comfortable even after prolonged use, with the exception that my little finger tended to drag on the desktop. The series 4 gets around this problem with an extended lip at the base which the little finger naturally sits on. I find that the positions of all the buttons are very good and unlike a previous comment, all function perfectly (under win7 pro 64 bit). The rapidly adjustable pointer speed facility is very useful for working with different applications eg slow for image editing but fast for browsing.Please note that my hand size is a relatively small 185 mm from wrist crease to the tip of the middle finger so I cannot comment on the level of comfort with markedly larger hands.To sum up - expensive but worth it.