My sister gave me a Roomba--the robotic vacuuming device that is supposed to clean all by itself. She had received it as a gift, but after trying it out for a while, she decided it wasn't for her. She said her house is too big and the thing had gotten itself lost a few times.
I tried it out in the upstairs hall. I watched it for a while to be sure it would not fall down the stairs. It came to the edge several times and turned around so I figured it would be fine by itself. I left it and went off into another room. Then I heard a crash. Roomba had fallen down the steps.
Nevertheless, after a charge it seemed to have suffered no ill effects from the fall. So the next day I put it in the dining room. It whirled around for quite a while until it had depleted all its energy. It had collected some dirt--though I am sure our regular vacuum which has far more suction would have done a more thorough job. Still, the rug looked neater--and some small crumbs had been picked up.
Today I put it in our little library. Again it ran around for a while until it ran out of power. Again, it picked up some dirt. I should do an experiment and see how much the regular vacuum would pick up after Roomba has finished.
But it is a nice gadget.