I have posted my review of Microsoft's Laser Mouse 6000. Here is an excerpt:

Microsoft has provided a well deserved update to an already great optical technology. This product includes the new Microsoft Laser Technology which aims to improve performance at much higher levels than the previous optical technology, including the High Definition Optical Technology on other Microsoft mice. The technology is 6000 frames per second (FPS) - an improvement over the 2500 FPS of most of the previous optical mice. Other technology improvements that have been made include 1000 dots per inch (DPI) resolution (responsiveness), 85 million operations per second (MOPS), .18 CMOS technology (preciseness) and the Microsoft Intelligent Tracking System (smoother tracking). Unlike the Microsoft High Definition Optical mice, this mouse has a 600 nm laser providing optical input. Microsoft optical technologies have been well tested for many years now and work smoothly on most surfaces. It has been broken-in well with previous mice, so you know you won’t have any problem.