I wonder the same thing-especially since I haven't paid off my Trek Stache 8 yet!!! but on mild terrain, I doubt unassisted bikes will ever go away. I can't think but they will forever handle better, be lighter, and more nimble because of that. But for climbing especially, and I don't enjoy the twisty, "flowy" single tracks out there, I really appreciate the extra power, especially for sustained climbs. We live in a part of the Cascades of Washington that doesn't have a lot of flat spots. Riding here requires a lot of work. I live on a mile long 6% grade, and it's a slog with my stache, even with the dinner plate rear gear. I'm maxxed out on heart rate climbing it, and only managing 3 or 4 mph. In the lowest boost setting (eco) on my Turbo Levo, and I can manage 8-10 mph while maintaining a heart rate of around 120 bpm, and not top out the ciimb feeling like I need an hour in the recliner to recover. When you think about it, this means i could slide back downhill and do it all over again, so it has the potential to double or triple my riding. In the long run, i'm actually getting more of a sustained, lower level workout than I normally would, so it's a good benefit physically! I probably will wind up changing my 32 tooth gear in the front to a 30 or 28, to prolong the battery life. Gotta say though, it's really a gas to power up stuff I'd normally be walking!!! And when DMV finally yanks my drivers license, I'll have to get myself a powered 3-wheeler, and become the terror of the retirement home!!