I have the Nor-Vise with auto bobbin, and enjoy using it very much. Here is a link to Norm Norlander's auto bobbin video. In addition to this video, there are several others that depict some of the advantages of using an auto bobbin. As always, there are pros and cons, so weighing them for yourself is all important before making a purchase. The nicest feature that I like which was already mentioned is the fact that the bobbin takes up the thread slack without loosing thread tension on your project. It's also works nice in reverse when you want to unwind thread from the fly body.

Good Luck.

Richard