I've heard people say that Du Chun would be adequate portraying the lead in Song in the Clouds, character-wise. I'm not sure since I haven't read the novel, but perhaps they could fix the problem by lifting the ages of the entire cast? That way Du Chun won't look like Nicky Wu does in comparison to the rest of BBJX. I think the problem with poor Nicky is that although he fits the age range, the rest of the princes look so much younger than him that he looks more like their uncle - it's painfully obvious in the full cast photos when he's standing near Kevin Cheng and Yuan Hong. And then paired with 23-year-old Liu Shi Shi who looks young for her age...