I have weird feet. Plastics are warmer and more comfortable if you have little or no approach but everytime I wore my invernos for more than say, a mile, my shins would get torn up. That is, until I learned the tricks described above. Even so, I find my level of comfort greatly enhanced by wearing insulated leather boots.
Just try keeping the uppers loose when walking downhill and tighten them up when you are getting down to business.