Has anyone used a Robo Mower?

So, does anyone out there own one of these: Robo Mower

(I hope that link works, I will include the URL at the bottom…)

I would like to know if this unit behaves like an intelligent person cutting a lawn, or if it behaves more like a pool-sweeper, going in random directions until it bumps into something and then changing directions.

I would also like to know the limits of its programming. For example, can it be programmed to do one section of the lawn today, recharge, and do another section tomorrow?

It would really be nice to get input from people who own one of these units, so no salesmen please…

here is the URL again: