We have had the Shark for three or four weeks. Overall, it does a nice job and the navigation, while accurate, is somewhat difficult to parse into separate rooms. I have an open floor plan, so when I overlay the foyer next to the great room, the foyer rectangle ends up being part of the great room. Not a huge deal. I really like the spot cleaning capability and the self-emptying feature. In terms of cleaning, the Shark is a bit challenged by some ergonomic mats in the kitchen (leaves some detritus around the mat) and occasionally by dirt that is right alongside the baseboard. We have wood, tile, and carpet, and the Shark navigates all capably. As I have seen in some other comments, the rotating 'sweeper' brushes (the two horizontally spinning brushes) sometimes 'kick' the dirt to the side rather than brushing it into the sweeper. I'm not sure how you would fix that...it's just how the physics works out.