I recommend this Roomba very highly. My carpet has never been cleaner and the only work involved is cleaning it up after it is done. Since I have a Golden Retreiver, this has to be done each time but it only takes minutes to do. I have it set to go off at midnight every night. I also have the Scooba and also recommend it.
He's fantastic on hardwood, but leaves a little to be desired on carpet. Registers under couches can be problematic. Cleaning him is a breeze but you have to get him reassembled perfectly or dirt can go behind the receptacle. He is persistant and thorough to the point that he sometimes seems like a "stalker". Overall we are extremely happy with our Roomba 560.