I only care what goes in the bobbin on my vintage machine. it doesn't hold much, so I want a thin thread. Guterman is fine for me. Other than that, I am trying to use up a few of my stash. 'Course, I'll wish I hadn't when I need to sew on some apparel and can't match it. Both machines will sew well with C&C, Guterman or Connecting Threads, so I don'r worry.