Do you own, and regularly use, a robotic lawn mower?

I was reading an article about them here The Best Robotic Lawmowers and was intrigued by the concept. They are supposedly quiet, energy efficient, and require low effort. So far, they are certainly not a good fit for my lawn due to: size, falling tree branches, animal activity, etc. But they seem like a good application for a smaller suburban home.
Do you own one?
How often does it need to mow? Do you let it out daily? Does it take a much longer time than a conventional gas mower?
How complicated was the border fencing installation? Do you need to bury the wire a certain depth?
What happens if a squirrel digs up and breaks the wire? Does it go rouge and savagely trim Mrs. McKeever’s Delphiniums to the ground?
What prevents a covetous neighbor from picking one up and walking away with it?