It's got a better chance of falling down curbs and stairs more gracefully with two wheels? Getting back up is another problem, though. Also, it might be able t

It's got a better chance of falling down curbs and stairs more gracefully with two wheels? Getting back up is another problem, though. Also, it might be able to navigate spaces a bit easier. Finally, it looks slightly more human since we're bipedal and it's bi-wheel.