I read Shanghai Girls and enjoyed that immensely. I don't think Dreams of Joy lived up to its predecessor. I liked the content and background of the story, communist China in the late 1950s, but I think I would have preferred a whole new set of characters. It would have been a longer book though.
I think I never truly understand Joy. Even near the end, she still had many of the same habits and temperament. Although she had been through great difficulty, I'm not sure how much character progression happened. I appreciate the work See did to construct this novel. It's historical fiction geared towards women and their relationships, so you can't expect an exact piece by piece description, right to the tee, about everything in China in this period. There was enough given to understand the atmosphere. Possibly, the whole depressing nature of China in this time sunk the book a bit.
I'll read more of See's work in the future, and if you like her other books, you will like this one as well. There just isn't the glamour present from Shanghai Girls.