Excerpt: my old ball track had the ball on top ,with l/r on the sides. this logiteck has the ball on the side. it is somewhat clumsy for me because I have ataxia. this condition causes my hands to be unsteady. I am making the best of it. if it does not improve, I may try to find another mouse that is more comfortable.
Excerpt: I needed to replace a Logitech Trackman Wheel which has been replaced by the M570. This isn't even close to the quality of the Trackman. I intended to use this primarily for CAD work. One of my unique issues is that I am missing half of my right thumb which was not a problem at all on the Trackman but the little blue ball on the M570 is small and light, it feels cheep and is hard for me to control precisely. I loved the silky smooth motion of the heavy red ball.
Summary: I have been using a usb wired versions of this trackball for a number of years. I bought this as a replacement and there are some issues. After about an hour the mouse motion becomes jittery with a short delay. I've updated all the drivers and installed the latest version of set point the Logitech software this is on Windows 7 x64 desktop.
Summary: I bought 2 of these around the same time (Jan 2011). One of them have left button completely worn out (it does not register well when clicked) already. Another one already squeaking. Logitech quality has gone down so much in last few years. Every devices they have these days are really fragile and lightweight. I have owned 2 dozen mice and trackballs. This Logitech Trackball is by far the worst in quality.
Summary: Whoever designed this trackball obviously never spent much time using them. To be effective and precise, a trackball needs multifinger control, not just a thumb. With this design the user will be spending most of their time correcting mistakes which one finger control inevitably invites. Just as it's not a great idea to steer a car with one hand, it's also a bad idea to steer with just one finger, especially if it's the least articulate digit on the hand, the thumb.
Excerpt: Does not have a substantial "feel." Trackball feels sloppy and loose but operates OK. USB Receiver very small and difficult to remove from its storage slot in the bottom of the unit.
Pros: Accurate Tracking, Comfortable Design, Fast Response, Works On Any Surface