I use a 1941 cast iron Singer exclusively, though I have several much newer machines. My Singer never does anything stupid---like randomly break the thread in the middle of the seam by changing its own bobbin tension---and if something does go wrong, I take out the bobbin, reinsert it, completely unthread it and rethread. Problems have always been solved. I also agree with the others....they are workhorses, sentimental value for some and just a great sewing experience every time.