Only trackball I can find with a thumb-ball, good contour to my hand

Third one I've bought, the click mechanisms seem to wear out after a year or so of heavy usage

accuracy, dependability, comfort, and durability I would say are the defining qualities of this mouse. It is comfortable to use for hours on end, easy to clean, last forever, I have 4 of these mice, one of them I have had for over 6 years, it's showing...

Only con is price, I don't like paying 30 dollars for a mouse, but considering it's the best mouse I've ever used, that doesn't stop me from buying

I work online, from home, and this thing really makes my life tons easier. On a busy desk, I do not have to dedicate a half acre of real estate to a mouse. And there are no wrist problems to deal with at the end of a 10 hour day

I cannot think of any. I came to the Trackman from the late M$ trackballs. They were good, but the bearings, which were metal in them, wore out in two years. No such tomfoolery with the Logitech. Bearings seem to be teflon. They do get dirty, but a few...