I live in CA. We had a super hot ride across the desert with the 13" on and we just about died from heat stroke. So I removed the windshield und just kept the inner bubbles (similar, but not the same as the double). This was fine for riding around town in the heat, but there was almost no air deflection A couple of weeks later (in July) we went on a ride from San Diego to Monterrey and I was too lazy to put the new 11" windshield on before the ride. Not only did we freeze half to death riding up the coast (if you have ridden the NorCal coast in summer, you may understand), but the buffeting was horrible. I don't know how close the double is to that experience, but I was so happy when I got my 11" installed right after the trip.Thanks I am 5"11 and was thinking the 11" as well. The double is tempting.