They definitely make it easier to clamp the corners together and it's a well made tool, it's a bit tricky to get very boards with it which I do If you don't address the manufacturer harshly, since the design allows boards of different thicknesses to be joined together, it would be very difficult to design the clamp so that it didn't have a bit of flexibility when pushed in. Overall, this is a good processing tool that's accurate enough for a closet. Workmanship, they are not precision tools for machinists, but they are accurate enough for most woodwork. If you want, you can set them with absolute precision like almost any woodworking tool, no matter the price.