I have been using the unit on a constant basis since I purchased it. It has been a remarkable timesaver for me in cleaning small parts and rescuing rusted hand tools from the dead.I still give this a five star, but the heating system is deficient. Fortunately this is compensated for when the ultrasound is activated, it actually heats the water better than the built in heating element due to the amout of ultrasound energy emmitted by the three transducers.For best results fill the tank with the hottest tap water you can get and place the parts and cleaning solution in a ziplock bag for immersion in the hot water (avoids cleanup from contaminating the machine itself with potentially corrosive liquids like vinegar for rust removal).
Jason 
