I used to have the old MX Revolution mouse and loved it - it worked smoothly and efficiently for years. When it died, I've got the MX Master model which is a HUGE leap back. Thumb buttons are tiny and hard to use, the side thumb push platform is unreliable and the Options plus software is a disaster. It stops working with every PC hibernation and need to be manually killed in the Task Manager and then relaunched. Don't think I will ever buy another Logitech mouse.