The power of your motor is the next most important component of an eBike. Don't believe the hype that power is all about watts (i.e. a 750w motor is not necessarily more powerful than 500w, or even a 350w motor) or volts (although, all else equal, a 48v system is more powerful than a 36v system... but things aren't always "all else equal"). A lot more goes into it the power equation. The biggest factor, which is rarely discussed, is torque (NM, or Newton meters). Is it hub drive, mid-drive, or front drive motor? Is the motor geared for speed or torque. What most people really want in power is hill climbing ability, and you need to compare bikes side by side on that to get to the truth of that power question.
At Tower, we use a specifically designed high-torque 500w/48v brushless geared rear hub motor. We sacrifice a little high-end speed for exceptional hill climbing high torque. The torque measurement of our motor is an outstanding 65NM (Newton meter). Our eBike will still go 20 mph, which is plenty fast, trust us, but you'll really appreciate the ability to climb any hill you face. In fact, 20 mph is actually a little too fast and we factory set our speed limiter to 18 mph because that's all most people will want to use. You can unlock the full speed if you like, but most won't need or want that.