Used it for the first time on 1200 sf of polished smooth slate floor, 18" grid tiles with 3/8" grout seams. Picked up lots of dirt, but left anything that had dried on - like fallen flower petals. I (and my cleaning lady, who had similar reaction)would like this unit a lot better if the brushes had scrubbing power. Its much quieter than I expected. Dries fast. I suspect its best for hardwood floors in bedroom and living room environments. I don't recommend for kitchen areas.