Interesting point: if we need to know two things, one of them being air temperature and the other being [windspeed or windchill], the second thing ought to be w

Interesting point: if we need to know two things, one of them being air temperature and the other being [windspeed or windchill], the second thing ought to be whichever delivers more overall value. If you can figure out how to dress based on either one equally well, then it comes down to what else can be gleaned from windspeed vs from windchill. I would tend to agree that windspeed is more valuable, as it's better at readily telling you if an activity you're planning to do, which is only possible under certain windspeeds (like using a tent or something), will be doable.