Bottom of the NC and NS are similar. The reason they say NC is "tapered" is that it's more generous through the *thigh* relative to top block and lower leg than the same size NS (which is slim and straight) and obviously the PS which is a beanpole leg. So if you've got reasonable thighs, but don't want to size up on the top block of NS (or have the same size NS drag down because too tight through the thigh), then maybe you need the NCs which is what I have done. Still strectching mine out though, so will see whether i made the right call. If not, then NS here i come...
I would have to say that if you're buying your first APCs online, without a fitting, then you are taking a punt.
