Because this mouse is optical, there are no rollers or gears to get dirty. It is responsive, the IntelliEye optical sensor scans 1,500 times per second, giving you precision with a minimum of movement. The movements across your screen will be smooth and fluid, not jumpy or jittery as in the old style mouse. You can move backwards and forwards in your internet browser without movement, just the click of a button on your mouse.

If you would rather the two buttons have other functions (such as cutting and pasting) you can reassign them to those tasks, in fact, with IntelliPoint software that is included with the mouse, you can reassign any function you wish, including the main function. You have five buttons and the trackball available for assigning; this mouse is capable of being totally optimized to your particular needs and conditions.

This could very well be the best trackball mouse ever made, many people absolutely love it. Unfortunately, Microsoft discontinued this mouse and it is very hard to come by. However, if you view this page for the Microsoft Trackball Optical Mouse on Amazon you can find some sellers offering used mice for around $100. If you really want a new one be prepared to fork over upwards of $300 for it. C’mon Microsoft! make this mouse available again please!!