It's been roughly 5 years since I first started using these mouse. That's right, I had three pieces. The original X-710FS, in which the wheel failed after only six months but else functioned flawlessly. The wheels failed again on my second X-750. One year later, A4Tech X-710MK was behind the wheel as well. So I went ahead and bought 718, and it's worse than every A4 mouse. I got it home, set it up, and replaced my 710, which worked OK on a standard table top but had some issues with the wheel. Consequently, the new one wobbles and the pointer flickers, as if I had purchased low-quality goods for $9. The laser system appears to have undergone a negative transformation, since the hole is now significantly smaller. The plan is to return it to the retailer in the hopes of exchanging it for an F5 laser the following day. To be honest, I never imagined a modern optical mouse giving way to a laser mouse.