My daughter visited Harbin two years ago and said it was amazing. The pics she took were pretty incredible.
Harbin took a definite negative, (it's climate) and turned it into a reason to visit.
An interesting thing about the city is that it is so far north it had a lot of Russian influence. The pics she took of the city showed a building with the 'onion' dome of Russian architecture and the street view I saw looked very European.