Has anyone had experience with one or its competitors?

My son bought us one last week at Costco, and we are finding the thing is much more effective than we dreamed. Our house is pretty cluttered with furniture that old people collect over the years, which I assumed would stop or trap one of these robots, but it has not. The owner has to give it a fair break by picking up stray charging cables and shoes with laces and the like, but otherwise it is programmed to get out of most situations.

I had just vacuumed & mopped the day my son brought the gizmo in, yet the dust container filled up each time it returned automatically to it’s charging station, finding dust we had missed in our cleaning routine. The machine takes about an hour and a half to fully charge and runs about for a bit over an hour. It came with one infrared device that can be placed at a door, which the Roomba recognizes causing it to turn around. All-in-all, we are pretty happy with it except it is noisy on the hard floors, but not so much on carpeted areas. Goomba - the name we gave the new member of the family - will do a nice job on the collected dust bunnies under the bed you never seem to get to, as long as the other stuff you hide there is removed.

This Roomba goes for $350 @ Costco.
The company also makes a similar one to use in conjunction with the dusting one that is said to mop hard surfaces.