The pedal sensor alone is not enough to determine how the bike gives power. There's a complete system of sensor, controller, user control panel and motor. The most important factor is the software in the controller.
There's two common systems:
Kalkhoff Impulse, Bosch and Panasonic use a torque multiplication system where the pedal torque is muliplied by selectable amounts. The advantage is that you can control the power with your feet like on an unpowered ike, but you get the disadvantages that you have to pedal hard to get high power and you can't get power without pedalling.
Many other bikes use speed control, where the sensor telss the controller when you're pedalling, whereupon the controller attempts to maintain a speed fixed by the user control panel. This has the disadvantage that you can't control the power at very low speed, but the advantage is that you get much better control over the power that you want to give at any other speed. For instance, if your control panel was set to level 2 (say 10 mph), you'd be pedalling on your own above that speed, but as you slow down past 10mph, the controller will start to feed in more power. The slower you go, the more power the controller gives as you struggle up the hill. These systems also usually have provision for a throttle, which enables you to adjust the target speed to anything you want.The throttle has many advantages. If you fall off the bike and injure your knee, you can still get home. If your crank comes loose or you get a crick in your knee or cramp, you can keep going. Pulling away from a stop is a lot easier when crossing main roads or doing steep hill-starts.
There's loads of other systems too that are anywhere between the two and the systems I described above are actually more sophisticated than I described. I simplified them. They all work, and there's times when any of them have advantages. I can't see that either system gives a reason to choose one bike over another, except if you need a throttle for whatever reason.
Normally, people come on the forum and say how far and fast they want to go, how hard they want to pedal/how (un)fit they are, how much they want to spend and what their special needs are.
You can fit mudguards and a rack to virtually any bike.
If someone comes on the forum and says that they don't know anything about electric bikes, but they want one that's yellow and black, full suspension, about a 400wH frame-mounted battery, 27.5" wheels, for a budget of £3700. I'd be very suspicious that they worked for Wiggle.
