Smooth tracking, positive scrolling with slight indents as you move the wheel. Clean clicks on the buttons. Scroll wheel clicks too. Left and right scrolling by pushing the wheel left and right. Works out of the box with Mac with no drivers needed. However, you can download a preference panel that will give you extra abilities such as reprogramming the keys, key combinations, etc. if you need that. Personally I don't.I wanted the following things: Optical mouse (not sure they even make the ones with the ball anymore, good!) Corded not wireless (batteries are a pain), real left and right button, a scroll wheel, and reliability. Of course all at a good price. If this sounds like you, stop here. The feel and quality of this mouse is right on the money. Very happy.