I've had my BMW C evolution for almost 2 years. In that time, I have not been to a gas station once (I have two cars that I should sell)! I'm in SF and ride almost exclusively here short of the odd cross bay trip.
I have a little more than 10k on my bike and it is hands down the most fun I've had on a two wheeler. Torque, Torque, Torque!
It costs a little more that $2 to charge and I get around 65 miles per charge. I've changed to solar for my electricity, so I have almost ZERO carbon footprint!