I'm looking into getting an ultrasonic cleaner. Harbor Freight has the Central Machinery 2.5 Liter unit and Northern Tools has the Raytech TS-2500. I downloaded both manuals and they appear to be the same but the Central Machinery unit lists for $80 and the Raytech lists for $160. I'm wondering if they are the same unit or similar units of different quality. Does anyone have experience with these units or ultrasonic cleaners in general?