I love this trackball. The ergonomics are perfect, incredibly responsive & the button layout exceptional, especially for such a small mouse. I like that it uses individual fingers to manage left-click, right-click and trackball, making it easy to click and drag. Many competing products have right-click buttons, so they work with the same finger as a trackball, making right-clicking impossible. There are also lots of thumb buttons, all of which are fully customizable. This is a very beautiful design. Every operation is intuitive and comfortable.