The question is not if you can do it faster than the robot, but if you can do it faster than the time it takes to start the robot. If it was necessary to stand and watch while the robot was working then there wouldn't be much point. If I spend 30 minutes vacuuming each week and can save that with a robot, then at $15 per hour its less than a year to pay off the most expensive model ($350). I think it sounds great, and I'm not sure what the value of having freshly vacuumed floors everyday instead of only once a week would be, but then it's probably paid off a whole lot sooner. I look forward to hearing more from Roomba owners.