A trackball mouse is more accurate than a trackpad on a laptop. It usually takes time for a person to adjust their grip on the trackball mouse. But once it is convenient, then it becomes an asset in your work life.  It helps to form vertical and horizontal lines. A trackball mouse is also useful for people who face wrist pains due to long periods of laptop usage. Most programmers and graphic designers find trackball mice more efficient due to their adjustable models and availability of multiple buttons that improve the speed of their work. It also provides better control over the work that a programmer is trying to accomplish.