While there are many benefits to having one product that can both vacuum and mop, some customers prefer keeping these two jobs separate. A robot vacuum can be working in one area of the house while the robot mop is focused elsewhere. Or, you can program them to work in perfect sequence to cover the same room. The Braava jet m6 uses a Precision Jet Spray mopping technique which sprays the water or cleaning solution in front to loosen dirt and sticky messes while the Roomba Combo products use a pad saturating process during mopping. If space for two robots and two charging docs is a concern, a Roomba Combo product can be a better choice for saving space.