I wear merino in layers while in the back country and usually start my morning hike with just two layers consisting of a 125 and a 210 and a light jacket. On days with no wind this is great the elevation gain, no sweat, and when I reach the top I add layers. I was thinking of adding a lightweight windstopper base layer, maybe on top of the merino for days the wind moving (every day in Wyoming) The merino doesn't hold heat that well in a wind from my experience, and most of the time I don't need the heavy shell. Any experience with a garment like this? I don't need another jacket just a base top that blocks wind well.