Bjorn3D posted his review on the XG Lazer Laser 2500 DPI Mouse. Here's a taster:

XG Lazer Laser 2500 DPI is one of the best gaming mouse available. The maximum resolution of 2500 DPI is just amazing. In fact, I often feel that it's way too fast at 2500 DPI for my 19" LCD monitor. However, I do use the mouse routinely at 1200 DPI under windows and the performance is really noticeable compare to the old 800 DPI that my Logitech MX510 offers. I am able to move across my desktop with less hand movement. The ability to quickly change between 6 resolutions (from 600 DPI to 2500 DPI) is great, it offers the needs for different people as well as different applications. Not only does the mouse offers great precision and speed, the amount of customization in the buttons is also limitless.