We have 2 roombas and we love them. Its also amusing to watch our littlest schnauzer stalk and attack them while they are working.
We always haul one to SoWal and have it programmed to sweep the broad expanse of tile in the main living area in the middle of the night. Each morning when we come downstairs we find it in its recharging station with a load of sand in its bin. Not quite sure where all the sand comes from?
At home, we dock the 2 roombas in a nice quiet, secluded spot, hoping that we'll be surprised by the appearance of a 3rd little baby roomba one morning. That plan hasn't actually worked so far.
