I don't have a Featherweight, although I would like to have one in my collection, one of these days.
I buy the old sewing machines because they sew like can't believe until you've tried it. :)
A big old tank of a Kenmore or Singer in a solid cabinet is pure stability when you're wrestling with a king-size quilt and trying to get it quilted.
So smooth - because they're so heavy! Think about how a Cadillac or a Grand Marquis just sails along and glides down the road. That's what the old sewing machines do.
I learned how to sew on a 1956 Singer and trying to find its twin is what got me started on collecting the old machines.
I've been learning how to refubish them myself and I only rarely have to resort to a repair shop - as when replacing the two internal belts inside my Kenmores - that's not a job for a home hobbyist without special tools.
I can strip the machines and clean them and put them back together and they're beautiful and nostalgic... and they sew! Oh, do they sew! And a few of them sing you a happy little song while they do it! :)