Haven't used a tumbler yet but cant wait to get one.
Ultrasonic cleaners are good for cleaning things that have dirt and gunk trapped inside them because the cleaning fluid washes it out from all the places where you cant poke something in to clean. eg: jewellery, watch bands and sunglasses. They cant remove stuff like rust and corrosion and they cant take the oxidisation or tarnish off metals. That is something that needs some kind of abrasive action such as the tumbler.
