I own  four of the irobot sweepers, they are very handy to have but do require more care in alot of ways then your  regular sweeper.  I  would not want one if I had a pet as the pet hair gets clogged up and very hard to remove on most models.  Where you can use your regular vacum cleaner and put it away these units require alot more tender loving care but come in very handy and you would be surprized as to how much dirt that they pick up.  I still use my rainbow at least once per month for heavy cleaning and use the robots in between,  They do get into trouble and you have to make sure that there is nothing laying around that you don't want them to get tangled up in.  They are v ery handy my biggest complaint is that the chargers and batteries sometimes don't last as long as they should and they are not cheap.  As far as the Irobot company as long as your unit is in warranity they give you no trouble   fixing the robot for free, you do need to register it. They have been nice to work with.

                                                                                          idealgem