What I think is funny, is that some here seem to misunderstand what an E-assist bike actually is. With an e- assist, you still have to pedal, and you still get a workout, you just go faster with a given effort.
Though I don't have one, the local bike shop here let test one extensively, not because I was going to buy one, but they too wanted to learn more about it and wanted a review. The one I tested was from Specialized. The ride was incredible. When I first got on the bike, I was amazed at the acceleration. i got up to speed very quickly, but still had to make the effort. I live in Western Pennsylvania where it is very hilly. The assist worked well on the hills. It was nice, but again, you still had to make the effort, you just went faster.
If I had a very long commute, in a very hilly area, I think it would be great. You could cut the commute time down considerably, making more time at home for the family, and at the same time, have the same benefit of the exercise.
They are not mopeds, as some have suggested. I am sure some allow for power without pedaling, but those are not e-assist bikes.