I have the Surly Big Dummy with Bionx pedal assist and my sweet sweet wife rides an xtracycle edgerunner bionx assist.
We bike commuted before, but it was spotty and depended on a lot of factors. We got the electric kits and haven't driven to work in 8 months. We can also do costco runs, all in town running around including hot dates, and we can expend as much or as little energy as the trip/weather dictates.
We sold a car and the other we dropped the insurance and only drive it for fun things- like backpacking, snowboarding and the like
We've already saved the cost of one of the electric units(cost per mile of driving a car, insurance etc) and are well into the 2nd.
My ride in not so pleasant weather, but perfectly comfortable under waterproof gear
Sweet sweet wife at 19 degrees F