I've had my Delta 50-850 for a few years.  It worked pretty well until I moved into my new shop.  I attached it to my metal ductwork and it just doesn't have the power I now need.  Also, I bought a remote transmitter which saves alot of time going back and forth to the machine.  The only problem is that when the remote is pushed, about half the time the breaker trips. Because of the problems I'm having, I've just purchased a new Oneida Dust Gorilla.  It's a cyclone dust collector and hopefully will have the power I need.