I use my Garmin Edge 705 for "everything": speed, cadence, power, ride tracking, and navigation. Even on routes I know well, it's convenient to know the distance to the next turn/stop. Like last weekend on an event, when we broke a wheel: it was convenient to know total distance to finish (since the event markers had shown a particular inconsistency), so we could confirm if it was possible to limp it in (which we did...two more spokes started to break through by the end).