My wife and I purchased a pair of e-bikes (I haven't seen any for rent where we are except at bike shops, and I can bike to work which makes owning one make sense), and yeah, they are -insanely- fun. Even for exercise they're great; you can pedal without pedal assist...but hit a steep hill, or have to stop due to traffic, having a throttle to get you moving just makes everything so much smoother.