Logitech's Dual Optical MouseMan
Logitech decided to go even further with product improvements by integrating a second optical sensor in this mouse. Both sensors work together; if the first one finds itself missing data the second one takes over and vice versa. Logitech claims that this makes the mouse less sensitive to different surfaces and that it improves accuracy because it's never in a situation where data is lacking. In fact, the Dual mouse can be used on any kind of surface - even a translucent grey plastic folder with a slightly raised grid pattern on the surface did not hinder its performance, although its rivals threw in the towel.
That being said, once can't expect miracles - it failed to work on a mirror. But anyway, who would want to use a mouse on a translucent folder or on a mirror? And that's where the problem lies. The other mice work perfectly well in almost all cases, so why invest a penny more in this technology? The answer is: because it responds faster. Although I have found that there's nothing more accurate than the Wheel Mouse in graphics applications (e.g. Photoshop for Windows), in FPS situations it is a huge advantage. It moves with exceptional smoothness and repositions itself to a fraction of an inch after long movements. This is the Logitech mouse that Quake fanatics will want to use. On the other hand, its fairly large, sloping shape is exclusively designed for right-handers. The shape is very ergonomic for general use but is a bit bulky for action games. The buttons and the knob have a smooth, light action and move exceptionally well. The third button on the left is easy to reach and can always come in handy. Furthermore, at a price of $49, it remains fairly inexpensive.