Take a look at this video....
 

this is a unscientific comparison of a regular bike vs a electric bike , using a course that is about 6 kilometers long and mostly uphill.....the guy doing the cycling on both bikes seems to be a avid cyclist , so his findings should have some merrit.

http://www.youtube.com/watch?v=qNjFv...eature=related

basically , the pedal assist electric bibke was able to make the commute in 25% less time then the unassisted bike { 20 minutes compared to 15 minutes] ..and I would assume it took less physical energy from the cyclist to achieve such a drastic reduction in time...

this would be like taking a normal 1 hour commute, and being able to do it in 45 minutes time.

it may not seem like alot, but it adds up. ...also, the electric front hub motor used in the video seemed to be a small wattage system...maybe 400 watts ??? Imagine if this same cyclist had done the test using a 800-1000 watt system....probably coulda made a normal 20 minute commute in only 10-12 minutes.

I have a 250W system. My 6.5 mile commute went from 55 mins to 25 mins one way when I went electric - and no sweaty clothes on arrival. The reverse direction is about the same for both, it's those inclines where the electric makes a difference. Bear in mind also the quality of the bike went DOWN when I got the electric. It is ugly and heavy compared to my "real" bike (that bike got stolen when I parked it at the transit station to avoid the hills).

I have another commute which takes 55 mins on the electric. It would not even be a consideration on a regular bike, for me anyway - 13 miles with inclines. Living in San Diego there are awesome cycle paths that parallel the freeways for long distances so it's the perfect place for commuting by e-bike.