Reviews for Logitech TrackMan Marble Trackball

It took a little while to get used to it, but now my hand doesn't ache at the end of the day. The only drawback is the lack of a dedicated scroll wheel, which just means I have to click on the scroll bar and roll the trackball up and down. A bit of an inconvenience, but a small cost to pay to not have an aching hand at the end of the work day.

I just got this rat (it's too big to be a mouse, and looks very rat-like in size and shape), and tho it's taking a bit of getting used to, so far I like it better than my old Mighty Mouse, which recently stopped working, and needed to be replaced.
I find it really comfortable, and it's a lot easier on my hand and wrist, especially for prolonged periods. I have big hands, so it feels just right for me. I also like the customizability of the button functions. I just wish I could customize the trackball itself, and enable it to scroll with it like I did with my old MM.
Logitech needs to add some sort of scrolling function for the trackball so you can scroll in any direction, like on the MM. That was the one thing about the MM that I really liked. The smaller "cruise" buttons are meant to replace the scroll wheel, but I find them very counter-intuitive, and I keep wanting to scroll with the trackball, but I can't, so I have to use those two buttons. I would rather have either a small scroll/tilt wheel or a mini-trackball somewhere on the rat, preferably up front near the big red ball, where my fingers can easily get to it. Either that, or somehow enable the big trackball itself to scroll, which would be a lot more intuitive and easier to get used to, I feel.
Software installation was no problem at all; it was very easy and straightforward. One caveat, tho: During the installation, it tells you to go to Logitech's website and download the latest version of their software, which, by the way, now supports 10.6 Snow Leopard. So if you have Snow Leopard, go ahead and make sure you download the latest version of it, and you should have no problems with it.
So, despite the "cruise buttons," so far I'm generally very happy with my "rat" and am now testing it to see whether I want to keep it or take it back. I'm tentatively giving it 4 stars for now, and will write an update when I've finally come to a decision on it.
Later...

Takes a little getting use to. The only thing I don't like about this mouse is that you cannot set the big red ball to "click." Reason why I rate just "4" out of "5" stars.

Otherwise, a wonderful mouse.