I have to lift up my hand and move my arm around to use it. With a trackpad all I need to do is move my hand over and flick my fingers for gestures. My wrist never moves.

Wait till you hear about a trackpoint. To bad almost nothing comes with one anymore.

As someone on a mac trackpad right now, the only gesture I somewhat regularly use is drag-and-drop. Everything else I'd rather do on the keyboard.

Takes time to move your hand to it.