[alistairSH]

Another clarification... many of the higher-end e-bikes act as a power multiplier. If you put 100W into the pedals, you get 200W at the wheels (roughly). To go ~20mph, you're putting in ~15mph worth of effort. For my wife and I, that means she can keep up with me with a similar perceived exertion, which is really nice.

Some of the less expensive e-bikes just have a dumb switch on the pedal to meet legal requirements. You can barely pedal at all and the motor will accelerate to 20mph (or faster). And some have a throttle that bypasses the pedals completely (typically not allowed on bike trails/lanes, though hard to enforce).