True holding your pen still when right clicking is frustrating. With my MX1000 Laser mouse I can customise all 11 functions to any program, you only need the numpad off your keyboard then for entering parameters, works fast as hell. On top of that I have my mouse speed spettings set at a ridiculous high level, when people sit behind my computer they ALWAYS lose the mouse because off the speed, so minimal movement maximum efficiency, relieves the strain on your wrist after a serious CAD session.