I have not used the clamp set due to the fact that the guide track stays in place without the need for the clamp set. Considering the price I wish I had not bought it and instead used the money for a piece of extension track.
Hey, I just tried one of these out (just bought one today!) and for what I'm doing, making doors, it's a real gift. This tool allows wood to be clamped to a guide rail from below; only, unlike screw/quick clamps, the rapid clamp is not limited to the extension of the metal portion of clamp itself. In other words, you might clamp a 24" length of wood to a much longer rail. Great for field work, simple, well priced. My kind of tool.