I'm a part time knife maker and I would love to have one, if the next show goes well I just might get one.
Agread that hand stitching is stronger, and on a few of my sheaths I'd have to change the design slightly to get the strength, but it would same time and wear and tear on my hands.
I think for my purpasses it would be a lot faster, as I am generally sewing 3 pieces of 9-12 oz. leather at a time. Right now I have a sharpened finishing nail set up in a drill press and use that as an awl and pre- drill all the holes.