So after Roberto (my Roomba S9) finished - 4 hours and 12 minutes on quiet mode to do roughly 1500 sq feet ("detailed clean" was WAY too noisy for me to deal with) I was pleasantly surprised at the quality of his work. I had put up all my dining room chairs and the stools at my island, which I'm sure helped. I went through and checked for the places I thought that he would for sure miss and the dog hair was gone. I am a happy person right now . I did get the one that empties itself which I heard it do at least twice while I was working in my office downstairs but well worth the extra cost since I would have been annoyed to have to empty him and set him back on task. Only downside is that he locked himself in my bedroom at one point. Glad he got behind the door but I would have been annoyed had I not been home to let him out and he didn't finish the job. So I give Roberto 4.5 stars although the only way he'd get 5 stars is if he figured out how to open a closed door. :)