The problem with electric bikes is that they're almost impossible to pedal over their legal assisted top speed (15mph). While they have a slight advantage going uphill, a lot of effort is required to go say 16 or 17 mph on the flat. I comfortably zoom past them on the road bike on the flat, have overtaken them uphill, and completely destroy them downhill.
I'm not in any was against assisted bikes though. If someone is unable to ride a conventional bike due to ill health or injury, then it's an ideal way to still get out and about and get a bit of exercise. They are however a big waste of money for a fit person. Not to mention the highly increased chances of a breakdown, and the limited 10-15 mile range. There's also the problem of an unfit person trying to get a heavy, flat batteried bike back home!