I was worried about it too, because my route is pretty close together. In the manual it says not to leave idling for more than 5 mins. I don't have very many really small jobs, so its basically 30 mins to an hour, that its shut off so I don't really have a problem turning it on and off. If I turned it on and off every 10 mins it could be an issue.
The mileage is definitely better than my gasser, thats for sure, it is nothing amazing around town but the highway is very good, about 13L/100km. I wish it was in MPG. Pulling a 16 foot enclosed, with like 2500lb in it.