Just an excellent product for left and right handed people who don't want mice running all over the place! It is my favorite type of mouse. I think it is just about as easy to use as a trackpad, perhaps easier since the left and right buttons are so handy.

The only space you need for this is the space that is the same size as the vice since it doesn't move; They are fairly long-lasting and that is a plus also; The main left and right buttons are reversible through software

It isn't as comfortable as it looks if you use it for a long period of time; After a while, the standoffs for the trackball need to be cleaned off; The ball can be lost

I forget how long ago I bought this - it must be four years ago or even six. It's second nature now, and a joy to use, even under Linux. They do need to be kept clean, obviously. They save a great deal of space as they remain stationary.

I finally gave in to my curiosity and purchased one of these when my 9y.o. Logitech "normal" mouse gave out. Gotta admit, I hated this thing at first, but now I can't ever see myself going back.

Smooth; accurate scrolling; Uses way less workspace; Easy to keep clean

None

I've bought almost every trackball ever made in the past twenty years - each one excels at one thing, fails at another. I have yet to find the perfect trackball. This one is without doubt the most comfortable one I own: it's a great shape for the hand and the exposed trackball gives you huge control...

Not a great product! There is no scroll wheel and the placement of the buttons is not at all comfortable for either short term or long use.

This trackball mouse is excellent! It's the only mouse that helps with my wrist fatigue. I am on the computer 40+ hours / week and couldn't do it without this mouse.

Smooth Movement

None

I have a very cluttered desk so my mouse was not getting frustrating to use. I bought the trackman thinking it would just be a capable substitute, but it exceeds the mouse in every way except scrolling... Find a way to improve the scrolling and it's pretty much perfect.

I like trackballs, especially the ones that allow manipulation of the trackball with your fingers instead of your thumb. The Marble Mouse is ambidextrous, which makes it more usable than other, right-handed models.

Accurate Tracking; Comfortable Design; Fast Response; Glides Smoothly; Works On Any Surface

No Scroll Mechanism; Secondary Buttons Small

Excellent User friendly mouse! No driver CD required.. and very convenient for using in designing!!

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.

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.

None..., period; When my last one failed after 12-15 years, I had to use a standard mouse; I thought I was gonna' die..