(If you want even more impressive mopping, check out the Eureka J20 at #6, which has a roller mop that supplies continuous fresh water, and siphons off the dirty stuff as it cleans.) Oscillating, spinning, or vibrating mop pads clean better than bots that just drag a wet rag around, https://www.youtube.com/watch?v=Lhgk6D1ayeM&