I have had a Roomba for a little while, and as far as I can tell, it does a pretty good job of cleaning up. Sure, some people have Roomba's so that they can turn them into ">a real life Pac Man or a"> ride for their kittens, but me, I just want a clean floor. Is it really covering the entire floor?
It looks like the Signal Theorist had the same question. The room lights off and a 30 minute long exposure shot answered that question. Every spot covered indeed.
-via Signal Theorist