This is their latest product. Just came out in 2010-09.
This is a improvement over the classic “Logitech Trackman Wheel” (the one with a red ball). Here's major improvements:
Overall, it got positive reviews. However, compared to the classic “Logitech Trackman Wheel” (red ball), the ball is a bit smaller and is a little more stiff to spin. This is also twice as expensive.
A veteran trackball user ( nsrpgmiv ), who has owned many different models of trackballs, made a comment that i think is very insightful and i agree with much. He pointed out that trackballs designed for the long fingers is much easier to operate than the thumb. This you can easily test yourself. With thumb operated ball, it assumes your palm sits still, thus your thumb movement are limited. In particular, going up and down is of limited range. With index finger operated ball, you can spin it easily, side ways, or up down. Your hand can easily hover over the ball freely. For him, he preferred the Logitech Marble than the Trackman Wheel.
The “Logitech Trackman Marble Mouse” is probably the best trackball on the market now. The ball is not the largest, but largish, and it spins well. It got 4 buttons. Got excellent reviews, and pretty cheap. (can get for $20) Missing a scroll wheel would probably be the only flaw, but for this symmetric design, it's hard to place a scroll wheel.
I'm not sure how flexible is the software for this trackball. From a physical operative mechanism point of view, the concept of trackball pretty much includes the functionality of scroll wheel. Some trackball has a button or re-programable button, so that when it is pressed, the ball functions as a scroll wheel.
At first, you'd think that “Logitech Cordless Optical Trackman” is the best one on the market now. Big ball, 5 buttons, cordless, plus a scroll wheel! However, after reading reviews, this mouse has several problems. The ball doesn't spin as compared to the Logitech Marble, the buttons are hard to use, the scroll wheel is not much usable.
This one is no longer in production.
The “Logitech Trackman Wheel Optical” was the most popular. The great thing is that it is well designed for right hand, and has standard scroll wheel for middle finger. However, the ball is small, and for the thumb. For general use, it's ok, but it lost one major advantage of trackball's ability to control the speed of the pointer position between slow and fast in a way that doesn't requires you to change DPI settings.
For reviews of other brand trackballs, see: Best Trackball Mouse.Disqus