It took a little time to get the Brava m6 to perform as expected. Not sure if it needed to wait for a recent software update, but initially it could only map 10% of the cleaning area. After three months of test runs to get the map right, it mapped out the first floor. I have a large house - first floor is around 2500 sq ft, so I started to divide the map into smaller rooms. That way the robot would not run out memory. I also learned to turn the lights on if it's dark because the robot can't "see" in the dark. Now it works flawlessly. I only need to refill the tank once for it to complete the job. Problems have been around detecting a full tank, and docking properly. I use it almost every day (except the days where it can't detect a full tank - even though it's full).