I've had one of these since November and have done over a hundred miles on it since then. I use it for my commute into London, getting to and from the station at both ends....has saved me 40 minutes a day (though I may end up fat through lack of exercise!)
They are very easy to ride and maintain and I have had no issues with it; solidly built, well proven and plenty of aftermarket parts and information available. You can even create your own custom firmware to increase speed amongst other things if you are that way inclined.
Police I have passed have not batted an eyelid....I think as long as you don't ride around on the pavements amongst pedestrians like a knob no one cares. Getting to be quite a common sight, they make a lot of sense in a city and, from what I understand, the DfT is currently consulting on the future of transportation so things might change.