Interesting....
PROS:  Tried it out in rainy 35*F- very warm over a light wool sweater. Tried it inside out - doesn't work. Looks nice
CONS: Runs small in midsection...suggest size up. Seam threads coming loose after one week's light wear. Exterior coat fabric "catches" easily and pulls threads. Will not wear well.
Summary:  Idea great, better fabric would be appropriate.