I have just acquired a Singer 201 which has the reputation of being the best machine ever produced by Singer. It just powers through four layers of denim, the lining and the zipper when repairing DH's coveralls. No more bunching of thread, balking at seam junctions, veering off course or breaking needles as my Janome 6500 does. My 201 just sews with no complaints about thread tension or anything else!