I am an Asian, more specifically Chinese. I can't say that I'm very negative towards those of my own race because I grew up in a mainly non-Asian neighborhood. First of all, I do think Ziyi is pretty and can act but... I have seen many of her films along with those of other Asian actresses. It just gets on my (or our) nerves that she is getting all the recognition when other Chinese actresses, who have much more experience or/and much more talented than her are being overlooked. (My cousin who is much more fluent in Chinese than I and is a big fan of Chinese entertainment really dislikes her and most of her films.)
Another reason why some Asians don't like her is because they are more aware of her and her past. I do think "she was in the right place, at the right time" with her string of Asian-critically-awarded-recognized-films in the US. Americans only know her for her performances in the "Hero", "House of Flying Daggers", or the upcoming "Memoirs of a Geisha." Like others have posted, her reputation in Asia is
baaad, but like here in the states you can't believe everything you read. BTW: I don't seek any of these Asian paparazzi footage/news, so if I can come by it, it is well known. You can definitely argue that she parties a lot and that she had relationships with Chinese pros in the industry, but I think that her sleeping her way to the top is a rumor (with grounds). On the other hand, Chinese tabloids are worst than America. (Paps would sneak into a room when a woman is taking a massage.)
A lot of people say she doesn't have any cultural values. Obviously, I don't know her well of enough if this is true, but I do think it is her goal to become more well-known in the states. Which by no means is a bad thing, though Chinese in China thinks of her as just being greedy. I do love the fact that through her Chinese cinema is getting more recognition. Asian films (House of Flying Daggers, 2046), directors (Wong Kar Wai, Ang Lee), and actors (Zhang, Li) are getting recognized a lot more nowadays. She was considered one of the most Influential People In America by Time magazine (if that means anything). Also, she did win some Hong Kong based film awards for 2046 as best actress.
Then again, you could also argue that China is a sexist, patricial society and considers her as "wild" and "greedy" but I don't like considering that as an arguement. (Though many use it when defending Zhang.)
If you want a more Chinese-oriented person's opinion about her, I would suggest you go to IMBD's message board on her. There are some very good arguements. My words in this post are kind of a response to both boards.
*Sorry for the long post. I thought that I should give some background into this topic since I'd hate leaving people thinking that all Asians hate each other. Also, sorry if I just made this arguement worst. Be gentle .*