To begin, this is the fourth trackball I have owned. The first two were the old putty colored ones I used with my older Mac's and were much better quality. The last two were both the newer model K64325 - dark grey.

This my 3rd trackball mouse. Our first trackball was on our 8100 Mac and it was great. This one is the best. I wished I had bought it for the I-Mac sooner. The scroll wheel really make this one worth it's price. Editing Word documents and Excel spreadsheets is a breeze.

Have used a trackball for about 12 years. I compare using a trackball vs a regular mouse to be like riding a no-speed vs a 20 speed bike. Wouldn't be without it. And you do get what you pay for. The last Kensington Expert Mouse I purchased (before this recent purchase) was in Jan 2000.

This is the eighth Kensington trackball device that I've happily owned over the last 20± years. Having just purchased my 10th Mac-the new iMac 21.5", 3.2 GHz-I naturally "tried" Apple's new wireless bluetooth mouse.

Bought two. Been using this for years after some elbow pain using regular mouse. No more problems & large ball is easy to maneuver. Plug it in & it works.

I was pleased with the trackball, as many of the people in the post production industry use it. I was very happy with Kensington supplying a wrist rest in the box. The motion of the ball is very smooth and highly accurate.

Easy To Clean; Ergonomic Layout; Smooth Movement

BUttons

This trackball was awesome until I upgraded from XP to Vista 64 & then Win 7 64 bit. The driver/software is not compatible & they have no plans to make it compatible. It only works as a basic mouse under those systems, no programability. Under XP it was great with tons of options.

Function; Programability; Looks

Price; Mouseworks software not Vista/7/64bit compatible

Ive used the various incarnations of the Kensington Expert Mouse for nearly as long as Ive used a pointing device on a computer yeah, I was a late adopter of Windows, I held onto DOS as long as I could. No mice needed with DOS!.

Large ball; smooth motion; easy to clean

Hard to find out there, except for some specialty stores, or on line; Misleading name! Why is it called an Expert Mouse ..; when its a trackball

PROS: Large ball, smooth ball movement, comfortable design, large programmable buttons with great software, scroll wheel great IDEA. CONS: Tracking slightly jumpy at times. Scroll wheel is such a terrible design it feels and often acts 'broken'. Reviews are correct about the scroll wheel.

We've used Kensington ExpertMouse trackballs for nearly 20 years. The large ball, handy button shortcuts, and longevity have all been big plusses. The trackball beats a mouse for many of us based on personal preference, and features such as occupying limited desk space compared to the room a mouse...

same timeless trackball quality; lots of configurable buttons; kensington's traditional quality

scroll wheel feels cheap; no wireless model anymore; scroll wheel is a hit on traditional quality