i agree with everything that Allen says in theory but the reality is that in CA you are allowed to have a 1000w motor. As I said I have a Panasonic, and a Yamaha, mid drive and they do take good advantage of the bikes gearing but my 48v 1000w hub motor will outdo either of them on steep terrain yet stays within my states restrictions on top speed (20 mph) because it is wound for torque not speed which in a 1:1 situation you get to choose one or the other. If Panasonic made a higher wattage motor it would be great but they probably never will just for the US market.
I also prefer a throttle over a pedal assist system and still pedal all the time because I like to pedal. I find that I can find a better cadence relationship to the motor that way and like it better for stops and starts. Try both and you will be able to decide for yourself.