Fits great with or without under layers, Much better fit and flexibility than my Carhartt arctic extreme coat. Very warm, though Ive only had it down to -10. Slight itch on arms when not wearing long sleeves, but that will go away with either a few washes or just wear. This is pretty common with most heavy duty coats Ive owned. When it is time to buy another one, I wouldnt hesitate to buy another one of these. Especially since it is truer to size and costs less than Carhartt.