Summary: I've had trackballs almost exclusively since I began computing 20(?) years ago. Started with Microtech. Eventually went with Logitech and am now using the Kensington Orbit. There is no trackball out there that is perfect. Few are even adequate. The Marble Mouse and the Orbit are both pretty good. A blending of the best features of both would come close to ideal. The Marble Mouse has good button positioning.
Summary: Reasonably priced and functional - a good buy, but design could be better. Footprint is excessive due to length of housing. Secondary buttons are too small and awkwardly placed for easy use. Best for using on a permanent work surface, not travel.
Summary: I bought this to replace my MS Trackball Explorer as it was the closest thing I could find. The ball is in the right spot, but the base is too narrow and uncomfortable there are fewer buttons, and I didn't even notice there was no scroll wheel until I opened the package. Disappointing would be my impression. However, it is much better than a thumb based trackball mouse.
Summary: When I was looking for a replacement for my Trackman Wheel trackball for my laptop, I knew I wanted another trackball. Since they don't move around like a mouse, I don't need as much space to use it. As I move my latptop around and use it in smaller areas, this is very important. I was dissapointed to find that Logitech no longer made the Trackman Wheels and the cost of a replacement was prohibitively high.
Summary: I've been disappointed as I read that it can`t scroll. Fortunatelly, buttons could be reprogrammed. I find that I don`t use forward button (little button on the right by default) so often, and I choosed "universal scroll" instead. After beeing reprogrammed, just press it brielfy and scroll by turning trackball. One leave this function simply by pressing button again.
Summary: I finally got tired of having to clear desk space for my Microsoft optical mouse, so I ordere3d this product when it was on sale. The ball part works just fine, but the switches need a de-bounce circuit. It seems to take 30% longer to read my email because I have to go to the Trash folder to retrieve about 10% of the messages inadvertantly deleted because of switch bounce.
Summary: I'm an engineer using mu computer in the car. I have loved the Logitech trackball for years. I wonder who on earth could ever want to substitute the scroll wheel with the ball!? - And replace index finger left click with thumbs left click!!?? This is not Logic!!
Summary: For the most part this is a 5 star rated trackball but Logitech removed the 5 button combination (Large buttons pressed together) and thus removed the functionality of middle button/scroll wheel. When I bought my first track ball 10 years ago it had this function with the old MouseWare drivers. With the SetPoint drivers, it removed the 5 button. With my new computer with Win7, the old drivers are incompatible.