Its main drawback is that if during cleaning it bumps into a corner, a wall, a closet, or any obstacle, then it immediately turns around and leaves for another place to vacuum, leaving this area uncleaned. As you understand, in any apartment or house there are such obstacles. It cleans well where it passes. But, its logic is very difficult to understand. You have to turn on local cleaning to make him vacuum those areas where he ran into obstacles. Works well on carpets. He often vacuums the same places many times, leaving uncleaned areas where he ran into obstacles. Knowing about this shortcoming in advance, I would not have bought it. It is better to pay extra and buy a 900 series. This robot will be good in large open spaces where walls and furniture will not interfere with it.