These mice have been indispensable to me for the past few years. I had three of them. The very first X-710FS, in which, after a period of six months, the wheel started to fail although everything else functions perfectly. The identical issue occurred with the second X-750's wheels. A year later, the A4Tech X-710MK was likewise equipped with the wheel. As a result, I made the decision to purchase model 718, which ultimately proved to be inferior to all A4 mice. I brought it home, unloaded it, and replaced the 710, which operated faultlessly on the surface of a standard table, but the wheel had some issues. Therefore, the new one slips, and the pointer twitches, making it appear as though I spent $90 on low-quality merchandise. The laser system now has a different appearance, and unfortunately, it is not an improvement; the hole is three times smaller than it was before. I'm going to try to return it or swap it for an F5 laser when I get to the store tomorrow. I had no reason to believe that a contemporary optical mouse would be defeated by a laser mouse. I was wrong.