For me: • no need to take my hands of my keyboard when I need to move the cursor, so I can start typing again right away • you can make the cursor travel long

For me: • no need to take my hands of my keyboard when I need to move the cursor, so I can start typing again right away • you can make the cursor travel long distance by just applying a bit of hard pressure, no need to go back and forth on the pad • three-button, so I can use the middle button to paste (X11 copy/paste system), open a link in a new tabe, etc...