I also vote for the Mid Zeros. I wear them in the 40s and low 50s, when it's cloudy or windy, below 55. Anything above that, I wear knickers or knee warmers (which are more like leg warmers on me). I can't wear them in the 30s. For that, I have the Sub zeros, which are great for the 30s. Sometimes, I wear my Ibex wool/Gore Tex tights that are really for winter sports, in the low thirties.