I have an old Pfaff that I had before the embroidery Pfaff I got. Keep it as a backup, or let a friend use it from time to time. I have an Elna Lotus that I got even before the Pfaff. It's so small and portable, I take it when I travel. I have a mint green old Singer that's a bit bigger than a featherweight I got at the quilt show because it is MINT GREEN! And it was only $50. And my son just got me a featherweight, and I don't intend to part with that either. Sometimes I just like to sew on something different, so I keep them all!
Oh yes, and a treadle that does work, but is mostly for decor.