Originally Posted by Leisesturm

Right now the torque sense system worries you because you have no experience with it. If you got one you would figure it out just like you did the one you have. I have a TongShen motor on a cargo bike project that has stalled. David Hall has put a lot of time in designing systems that work well for a lot of people. I don't think you can get 250W even if that's all you want. Go big, or go home they say. Overkill is rarely a problem. You usually get a better built product and since you aren't pushing it to it's limits you get excellent performance and longevity.
Edit: I have heard it from too many different sources to continue arguing with it: torque systems are very easy to use. 'Natural' for want of a better word. You just ride like you always have. Start off with a low level of assist like you like to do and if it isn't enough you will know. It will probably be fine. To go faster you gear up. If your speed drops (going uphill) then gear down like you would (should) add more power. It will do that automatically anyway but there will be times when that won't be enough and you don't want to bog the motor. That's another reason to get the 500W motor. It can take some bogging at low speeds. Edit 2: Flats? Flats have not crossed my mind in a very long time. I don't carry tubes, patches or pumps on commute or errand rides because I have invested in tires known to be highly flat resistant. With a motor you shouldn't have to worry about the ride performance of tires like Schwalbe Marathon Pluses and if you wanted to put Rhynodillo or Mr. Tuffy tire liners in a Continental Gatorskin tire you would have an essentially flat proof tire. FWIW.