by jdeacon » 13 Dec 2005 19:11
I find it indispensible. Easier, quicker and straighter - you can't wander off to (or, worse, out of) the side in a moment of distraction. I use the Souber one as well. I wish it cut the keep box hole as well.
Do have at least a couple of practices on a piece of scrap 3" by 2", though. It's not difficult to cut the mortice fractionally too small, and you don't tend to find out until you've taken the jig off the door. You also need to get use to which hand does what: the up-and-down hand moves the jig's drill housing and the housing moves the drill; vice-versa doesn't work. The other hand applies a bit of forward pressure. The cutting takes place during the up and down movement, in several shallow cuts. It's more milling than drilling.
John