It's one of the best vintage models, many's favorite. The reason for not running the machine with presser foot down and no fabric is the excess wear. The presserfoot gets these deep scratches, the chrome/nickle wears off, and excess wear on the feed dogs as well. It's pretty common on any machine really. That said, this is a model that stands up to a lot of use and abuse, but I always reccomend to treat it with care.