Summary: I bought my first one in 1997 when I started to have pain issues in my right thumb and wrist. This was the only mouse on the market that was usable by the left hand. Once I started using this and switching hands on a regular basis I have had no more issues with pain in hand or wrist.
Summary: This is my third Trackman marble mouse. I just keep wearing them out which is not an easy thing to do. I even spilled a large glass of iced tea on one and after letting it dry out way only mildly surprised to find that it still worked just fine. That was my first trackman.
Summary: These are not for everyone. It takes a little while to train yourself to using it, deciding what functions to use for the secondary switches, speed of movement, etc. But, overall I cannot suggest a better product for any use.
Pros: This is my second Trackman, I had my 1st one for many years (15?) and the left button switch finally gave out. I can't imagine what the click-count was, but it had to be very high. I hope this one lasts as long. Mostly, I am glad this product still exists, it is sort of unique. Once you train you...
Cons: None..., period. When my last one failed after 12-15 years, I had to use a standard mouse. I thought I was gonna' die...
Summary: This is just the thing for older, arthritic hands. It takes a while to become accustomed to the smaller auxillary buttons over the larger "left cllick" and "right click" buttons, but after a few shakedown sessions, I got the hang of it.
Summary: I can't remember when I bought this thing, but it's been years, and I've taken it around the world with me. It's amazing. It's never failed. Once you get used to the slightly different button placement, you'll never go back. I've never had wrist problems with it, even after hours of constant use.
Pros: Incredibly durable, easy to clean, easy on the wrists, an absolute workhorse.
Cons: It does get linty fairly often, although it's easy to clean out. No scroll wheel/middle button. If you use those, then this isn't your thing.