A quick power-to-weight comparison of a Trek Super Commuter+ 8 and Pinarello Nytro is very telling. I picked the Trek merely because I am familiar with the bike. It may not be the most equivalent bike for comparison sake.
https://electricbikereview.com/trek/super-commuter-plus-8s/
2017 - 570 peak watts / 23.7 kg = 24.0 w/kg, 170W greater peak power.
PInarello Nytro 400W / 13kg = 30.8 w/kg or
22% higher power-to-weight, 10.7 kg or 55% lighter.
So, do you need the additional 170W?
I do not have a watt meter. The only data point that i have is an unreliable 800W from a store display test, which I disbelieve. I do not need the additional 170W. I certainly can benefit by dropping 10.7 kg in bike weight.
The choice is overwhelmingly simple in my case, because aerodynamic drag is not even factored into the decision. I would not be surprised if most of those additional 170W were lost to drag above 25mph.
https://www.cyclingweekly.com/news/...ro-become-more-significant-than-weight-316952
Aerodynamics is all-important over the cut-off speed. The Nytro only assists up to 15mph, so aerodynamics should dominate decision making. The Trek SuperCommuter+ 8 is a 28mph bike. The Nytro will crush the Trek over 28mph. I hit 35mph a few times per day on my normal route.
The perception of an eBike is very dependent upon your conceptualization of the experience you expect from the bike. Comparing a 28mph eBike on the flats is irrelevant to me. My average flat speed is 22 to 25mph. The worst case scenario for a Nytro design is 15mph uphill in heavy wind. I really do not care about uphill speed. The exciting part to me is downhill speed. Downhill speed is entirely dependent upon bike aerodynamic design, for my purposes.
So, my conceptualization of an eBike is the conventional bike design, especially wrt aerodynamics. My low-end conceptualization speed is under 15mph due to wind. My upper-end conceptualization speed is over 30mph, due to wind resistance.
The motor power and battery capacity plays a small role in my perception of an eBike, because the speeds between 15mph and 30mph are merely a means to an end. The effects from wind over 15mph are my primary concern in my mental model of an eBike.
You can accurately state your power requirements when you specify the length of time spent at your lower and upper power levels. My lower and upper power levels are one and the same. My power requirement is minimalistic. Therefore, weight and aerodynamic design dominate my buying decisions.
I subscribe to Orbea's efficient and sufficient philosophy. See
post #24 for complete detail.
In concrete terms, a 200W motor and 200Wh battery are sufficient. The efficiency derives from weight under 13kg and aerodynamic design. The lower your top-end speed requirements are, the lower your aerodynamic needs are. Lower aerodynamic efficiency mean lower bike cost. So, a person with a 20mph top-end speed has no significant aerodynamic concerns. The longer your power needs extend past one hour riding at 15mph, the greater your battery capacity needs are. Battery power is the most significant factor for an eBike's electrical system cost.
If you grasp the tradeoff principles elaborated in this post, you can optimize your eBike buying decision. You have no reason to fear buyer's remorse for spending less than $1,500 or more than $5,000 for an eBike, because you have found value that addresses your needs.