I wanted to confirm these findings and add something else. When my roommate bought it, I thought it was pretty useless. Even just seeing it in action makes you wonder how it get's anything done. It basically runs in random patterns and takes forever.

But after I moved to a different apartment, and he got his own place. I really saw how much work that thing was doing. I forgot how often the floors need to be swept to keep it clean. I plan to buy one myself once I move at the end of this month.