I have tried many different base layers from Sitka, Kuiu and Cabelas but nothing compares to the comfort of these First Lite merino Furnace tops and bottoms. I don't know what they do to make it so soft against your skin, but its amazing. This Furnace is also the warmest and heavyweight set I've owned. This is my go to base layer set when it's really cold outside.
All my merino base layers will be from First Lite going down the road.
Give em a try, I think you'll agree they make the finest merino wool base layer you can buy.