The main drawback is height of foot (from what I've read). If you can fit it under the foot, the machine will sew it, but it's not got a lot of clearance. The needles are not all that long (especially compared to the spears that came with SteveH's Polytype) so they aren't meant to go through a big thickness.
I could see doing a lot of harness repair with this - but there are areas of a saddle that would be too thick to fit underneath. I have also read that the teeth can be rather aggressive, and leave chew marks on some leather.
I'm looking forward to using DH's machine, and seeing what fun I can have with it. I think it will be really neat for dealing with canvas and tight corners and fun stuff like that.
