Bought the 15L upgraded model. I love it so far. I can put engine parts in that are covered with the brown oil glaze or even burnt on carbon deposits and they come out looking like new. It does take a while to heat up even when adding hot water to it, but what do you expect when the parts come out so hot you can barely handle them. The heater is not on a timer, the ultrasonic is. This was worth every penny.