Sune uchi (which is what we call lower leg cuts) accounts for 75-80% of the points that get scored in competition. You'll notice that both of the points Kaori takes off me are to sune.
You'll also notice that I've got the range completely wrong, which is why I don't get any flags for my attacks that get through. You're supposed to cut with the mono uchi, near the curve of the blade, and not down near the tape.
I'll try to get the video onto somewhere else for the benefit of non-FB people.