My son has one, (purchased nearly new) and absolutely loves it. He drives to and from work each day, mostly along a motorway, partially in town. It has cut down his fuel costs considerably.
Recently, he drove from Cheshire to me in East London, when I was in the process of moving, drove around there for two or three days, and when he needed to fill up cost him just £25.
One of my daughters also drives one, but a much older model. Again loves it. Only problem she has had with it is that the battery does not work too well, but she has overcome that by using a trickle charger overnight.
I would have loved to have a hybrid - but they cannot yet make these for small cars due to the weight and size of the batteries involved.