Whats the real difference between the various riding modes on eBikes, and how much of an impact does it have on power output and speed. Are we talking about a 10% increase in speed, or a 50% boost in power. And what about the presets - are they just a fancy way of saying eco mode or turbo mode, or is there some actual science behind them. Ive seen some eBikes with 5 or 6 different modes, but Im not convinced its not just a marketing gimmick. Can someone whos actually put in the time on an eBike tell me what the real-world differences are between the different modes, and whether its worth shelling out the extra cash for a bike with more advanced presets. And while were at it, whats the deal with the wattage limits on some eBikes - is it just a way for manufacturers to avoid getting sued, or is there some actual safety concern. Im talking about the bikes that are limited to 250 watts, but can supposedly put out 500 watts in boost mode - whats the logic behind that.