I'm like Herb in that I'm okay with the finger/box joint. I bought the Ibox jig after using a home made one for a while. The Ibox has the advantage that you can set it according the cut width instead of setting the cut width according to what is required by the jig.
If I was going to buy a DT jig I think I would save up and buy a Leigh. You'd have to search to find a bad comment about them.
Someone I consider a master woodworker once told me that a master woodworker is not someone who never makes mistakes. He is someone who is able to cover them up so that no one can tell.