I have that machine and so far it has worked fine. It does sound clunky, I think of it as old-fashioned as it sounds like an older machine. I haven't sewed denim but have sewed through multiple layers of folded fabric with no problems so long as I go slowly and make sure the needle is seated properly. Not a high quality machine, though, and if were planning extensive heavy duty sewing I would invest in a machine that has no other function.