Cougar Revenger Review @ Vortez
 

It would be fair to say that the Pixart PWM3360 is one of the most advanced optical sensors that is publicly available (the PWM3366 is exclusive to Logitech). Cougar have now implemented this sensor in the Revenger gaming mouse, which appears to be based on the 500M series mice already in their stable.

http://www.vortez.net/review.php?id=1217