My SIL has had a few generations of them. The newer ones are much better, but you still need to vacuum weekly. They don't do stairs (we have stairs to 4.5 levels), otherwise I would get one

My stairs and kitchen I could do daily...
I read many reviews on them and they have changed the brushes on newer models, so look for a Roomba model 500+. For the Scooba they said they needed cleaning after every use.