The 720 is possibly the most accurate device I have ever used. I usually stick to trackballs for their accuracy, but I have to admit the 720 is at least as accurate as my previous two trackballs, the Kensington Turboball and the Microsoft Trackball Explorer. Unlike the Explorer, the 720 had no tendency to slide. I was unable to find out more about the clutch function. With most mice, when there is not enough space left on the surface, the user would lift the mouse up to centre it. GWS claimed to have a way around this, the clutch function, which could be assigned to any button through the configuration software. On a basic level, when a button is assigned as a clutch, all movements on the X and Y axis are suppressed until the button is released. A button does not have to be exclusively assigned to clutch.