lol I don't have a machine for leather, but have others and have read through the thread, i would love to get one someday so gathering all the info i can. Seems a leather sewing machine is just like any sewing machine, from what i have read, can use a number of threads, needles feet and any number of add ons that will do whatever one needs.
I guess my question to all the folks on here knocking the sellers is how in the heck can they send you a machine tuned and ready for every single thread needle combo and gadget that you can think of? How do they know what you are sewing? what you may sew in the future and or what thread, needle and gadget combo you may dream up during your morning shower?
Sewing machines are amazing machines and at one time almost in every house, with a company or more selling and repairing in every town, not now they are dinosaurs living on borrowed time now and finding someone that even sews let alone can work on one is rare.
I had the great fortune in my working career to buy equipment for a number of trades including textiles it was always in our purchasing contracts to provide initial setup and training but on our part we had to know what we were going to be making start to finish, we had few problems but most all the machines no matter the trade had to be setup or fine tuned for what we wanted. I don't see how any company could provide this service to the private citizen without it costing a lot of money that the private citizen or the industry simply doesn't have.
Every person who has ever tried to machine sew anything will tell you that you have to know how to maintain them and tune them.
With that said if you cant get reliable training and service and have to be self taught buying a brand new machine isn't cost effective imo.