Hardware Logic posted a review on the Microsoft Sidewinder X8
A quote from the article:
>> Microsoft Sidewinder X8 Review
Today, we take a look at the SideWinder X8, the latest addition to the team and a first for Microsoft as a wireless gaming mouse. Incorporating their newfangled BlueTrack Technology, the SideWinder X8 a blistering fast laser sensor capable of on-the-fly adjustments from 200dpi to 4000dpi and boasting up to 75Gs of acceleration, trying to prove the sword is mightier than the pen. Building up from the original SideWinder mouse, Microsoft hopes to wow gamers with the X8's quick speed and control. Jump in and find out if this sword is worth wielding or if the pen really is mightier than the sword.
>> Microsoft Sidewinder X8 Review