I have been using the Irobot for about 12 years. I started with the original and progressed to the 880. It did a bang up job for 5 years and just went haywire. We retired and moved into our retirement house. It is not big, 1267 sq ft. I pulled the trigger on the S9+. It was not easy to spend that much on a "Toy". Well, it was a great investment. We installed new wood floors and this works perfectly on them. I run it twice a week. The floors look new.