Three major problems with this mouse: 1) No scroll wheel, which I can't believe I didn't notice in the specs before buying. Who makes a mouse without a scroll wheel You can program one of the two buttons to enable scrolling with the ball, which means you've now eliminated standard mouse functions...

If you want a trackball with a scroll wheel, you can't go far wrong with this.

Smooth scroll wheel; comfortable; performs well

Can get sluggish when dirty; care must be taken when cleaning

I had the old mechanical Kensington trackball. This one is much more sensitive and I shouldn't have to clean it like I did the old one.

I haven't used a trackball before so I have nothing to compare this to except for my Logitech mouse that is so responsive to my touch and this one isn't quite that. I was used to giving the scroll a twirl and having it run to the top or bottom of the page - just like that!

A couple of months ago, I paid about thirty dollars for a Kensington Orbit Optical Mouse . This trackball mouse is one of the best input devices I've ever owned, or so I've discovered since I first attached it to my laptop. I hate laptop mice.

The blue ball is big, one and a half inches diameter, great for easy and speedy handling and accuracy. The scroll ring is easy to use and allows me to scroll up and down in a more controlled manner.

it is the easiest to use. having arthritis, this trackball eases the joiint pain when using it. everyone should use it.

The idea, according to the simple, multilingual marketing spiel on the front of the Orbit Trackball box, is 'comfort meeting control'. Having only ever used a trackball in abortive attempts to enjoy the odd Missile Command cabinet, I wasn't entirely sure what to expect, but I've actually been...

Very good mouse, easy to use

Device is good but software .. When I defined Left Button as "click" I can not define it with button from keyboard i.e. LB + Ctrl. The only one definition is possible. Total disqualification.