I had never heard of this before so I went and looked it up. For me it is not worth the cost of $26. Its only purpose is to help you fold and press the binding that you have cut/stiched together. It appears to be a board with a slit in it to run your unfolded binding through and then an attached padded pressing surface to iron on. I don't see a need for a 'tool' to help me do that but everybody is different.
I have always pressed my binding in half before attaching but I have read on QB of people not pressing and getting good results.