I took A4Tech X7 as a replacement, I was very upset by the financial policy, X7 was programmed for free. It's downright gross. Physically, the mouse is 9/10, programmatically 4/10. Got pros: Fits perfectly in the hand, high resolution, glides perfectly on the mat. Very flexible setting, up to adjusting the sensitivity of the height of the mouse above the surface. Different cons: - Too hard wire, releasing the mouse, it spontaneously slides - To use the programmable buttons (side and top) you need to "unlock" the mouse by paying about $ 15 (there are 1000 trial clicks).