I haven't tried any other dupes for the Lululemon Define jacket but its hard to imagine a better one than this. Im 5'9 and bought the small and it fits perfectly. I typically wear a size 4 or 6 and would have bought the Define jacket in a 6. Also for my tall girlies, the arms are long enough to comfortably use the thumb holes at the hands.
Rating: [4 of 5 Stars!]