I have sewn threw 5 layers of denim and DH used it the morning after I got my 401. I think the guy is trying to blow smoke. I would be leery about letting him touch it. The gal and repair people at the local Singer center were amazed I got my machine for what I paid for it. Also let me know that if anyone wanted to do anything different than needed to be done to walk away. I would walk away if I were you.