We have 3 at our shop. 2 much older, and one moderately older. We use the 2 older ones to clean whole hydraulic units that come in, and the newer one to clean the internal parts before a final cleaning in an ultrasonic cleaner or by hand.
The older ones need more attention to keep running well, over time the nozzles will wear out and have to be replaced. The machine we wash sand-blasted units in needs this more often than the other machines for some reason... haha. The older ones also don't have a screen in-line so it is common to have to pull the nozzles out and flush out paint chips, o-rings, and bits of random **** out of the back side of the nozzles as they plug up. The newer machine has a screen filter and does a much better job of catching things like that before they make it into annoying places. The newer machine also has a much better floor grating system to keep that **** out of the sump in the first place.
Leave the lid open, or the insides will rust. Take stuff out promptly when the cycle ends, or it will rust.
They work pretty well.