I don't own a featherweight, but I do own and use my vintage machines which are all in treadles for piecing and quilting.
Why own a vintage machine because:
they are easy to care for and clean
can be purchased for under $50
they make beautiful stitches
they are designed for heavy use, to sew through thick fabrics like denim
true horse horses
they have a large harp space which makes it easier to quilt a large quilt
they have beautiful decals and motifs
their cabinets are gorgeous, a piece of wood art
treadle irons are a piece of mechanical art
all metal, no plastics
And they never die- their previous owner may be long gone, but these machines just keep on living.