We were on Expo, and had the experience of these racing, not only that a racing midget (not being rude) he was great to talk to. But it seemed all day that these were comming past.
I was on Expo as well as the guys on these doing laps of the campsite were a real pain. Its noisy and unnecessary.
Must admit I don't like them, don't understand the point etc. However haven't got one, and if I did maybe I'd change my mind!
However its like everything, as long as you are sensible, don't race round campsites, or just for going to the toilet, then I don;t see a problem. Doesn't mean I'll start liking them though!