I used to use irobot roomba 560. I brought it in from USA.
It's really a good clean but I didn't really like it because it is noisy. Noisy not coz the machine is noisy but it hits into our dining chairs and small tables so hard that the furniture moves. =/ In the end we had to put up all our small furniture so that it can do a good and quiet clean.
But the cleanliness is really good. My robot finishes a job in about 1 hr. I live in a 4 room flat. The robot only cleans the living and dining area.