Summary: I had a logitech marble mouse for 5 years. It was a tough and nice one until I screw up my ps/2 port by updating my motherboard bios. This trackball is an eye catching when I was looking for a replacement of my old marble mouse. If you like the marble mouse this is the best upgrade. It feels pretty much similar to using a marble mouse but with more buttons to use. The forward and back button located right above the left button saves a lot of movement when browsing the web.

The movement control is excellent. Better than trackballs using thumb. If you are not using any trackball, it would take a while to get use to it. It is perfect for FPS games as well.

There are two things bother me a bit (but not big issue). The scroll is a bit too far from the ball. You have to move your index finger further to reach the scroll. The little lock button is hard to reach as well. Another thing is for the calibration. Because of the location of optical sensor, the horizontal movement was tilted 45 degree when the mouse first plugged. This can be fixed by the calibration. The calibration function isn't so efficient. I tried several times to get it move correctly. After that, the trackball is perfrect and movement is precise. I got it from zipzoomfly.com with free 2 day shipping. Feels like my good old marble mouse is back. The only difference is that it has more handy buttons to save your mouse movement.

Summary: The Logitech Cordless Optical TrackMan is an extraordinary device. No more needing a square foot of desk space to manipulate a traditional mouse. All of the controls fall naturally beneath my hand, and many normal mouse functions can be either programmed or adjusted by Logitech's easy-to-use software

Moreover, I cannot understand the problems some folks seem to have with using this with a Mac. I've owned at least three of these, and used them with a Mac G3, a G4, a Mac laptop, and now a Mac Pro. It has performed perfectly--and 100% reliably--with all operating systems from (I think) 8.x through 10.4.8.

To be sure, it takes a little time (less than an hour) to adjust to using a trackball, but, that done, it is MUCH less stressful and much easier than a traditional mouse. And did I say it doesn't have to move around on your desk? Say goodbye to your mousepad!

The wireless connectivity is equally painless, and works flawlessly. There's just a single USB connection (from the transmitter) that can be placed just about anywhere out of the way.

I intend NEVER to return to another kind of mouse!

Summary: I found this wireless trackball very fun to use. It has all the programmable buttons that can eliminate a lot of cursor movements. For those who used to mice may found some problem with trackballs at first. But, it is easy to control after a little practice. I like trackball because I can use it in limited desk space. It does not need much space to move around like the mice.