Broadhead Pro Sharpener

[The Gopher]

Has anyone used one of these? how well do they actually work? how long do they last? I have just been using a file, and although i can get sharp broadheads, it sometimes takes me quite a while and i find it aukward. Also i notice that the one from 3 rivers looks just like the one that sells directly from alaska bowhunter supply, are they the same unit sold under different names? thanks for you help, Dan.