I have one of these. It works great. Its no more expensive than any other tf tool.
Make sure of your proccedure because it would be an expensive oops to nick it with
the router.definitely saved time and joints were real tight. Because of the shape
of the pocket I think, there is no gaps from shrinking etc.I also used it to attach
corbels to the mantel. Stays tight even when shrinking ocurrs.
(Sorry for cheating)