Yes they have auto fill and auto dump. The auto dump uses a shurflo pump so they need to be maintained but they will work well if kept clean. They also have a chemical metering system.
They are rated to about 600 psi, but will likely go higher if the pump and the system is in good shape. It uses 3 2 stage vac motors. They are not the standard 2 stage though. They have a higher rating. At 50 ft the vac is good. We have used 100 ft often on commercial with good success.
They are heavy. We never used ours on residential. It takes 2 men to lift it into a van or a ramp is needed. It also takes 2 full circuits to run it and if they are 15 amp circuits you have to turn the vac motors on 1 at a time and let them settle in a second. I always used mine on commercial where the circuits are 20 amp.
By the way, I wouldn't sell mine for less than 2,000.00. 650.00 is a steal.