On the whole, I have to agree with all of you on this one except hengcs. This was a nice try, but nothing more. The story and the acting are quite good, but the directing must be one of Zhang's weakest, and the rhythm, editing, cinematography and the way the topic was handled were rather weak. Although it seems that I found it much more emotionally rewarding than most of you (as I got almost moved to tears in certain moments - not the deliberately "cute" stagings of the little boy - I'm rather with hengcs considering this aspect), the artistic quality of the film seemed extremely low to me. Yes, it is more on the "artsy" side, and I found the Japanese segments , which were not shot and directed by Zhang Yimou and his crew (!) particularly rewarding, but the oversimplifications and pondering to the audience during other segments was sometimes almost unbearable. A very uneven film, I wouldn't recommend it to a fan of Mr. Zhang, but overall i still found it a good movie, with the positive traits outweighing the negative ones. I think the biggest problem while watching the film might be your own expectations, and the fact that the story offers an incredibly huge potentialof possibilities which are rarely explored. If anything, the film at times bites of more than it can chew, yet the result in my opinion isn't unsatisfying. If you take the film for what it is, you should have a rewarding experience. 

PS:
The biggest disppointment for me was the lensing of the Chinese segments. Having seen the excellent photography of some of Zhang's other films, this uninspiring work was a huge let-down. Seemed almost like it was made for a small TV screen and not for the cinema