XAI. The Kinzu is good too but my Xai is the best mouse I've ever used. It's the best PC peripheral I've ever used. I almost doubled my average FPS scores. It is so accurate, glides so perfectly, has such awesome features. I have not one knock against it. The material is just right, the thing is perfectly weight centered, the feet are perfect, the sensor is perfect, it's super accurate, it feels great, it's nice and rubbery, I can change settings on the fly between 16 different modes in the mouse with no need for external software IN game. Buy it. Seriously.