I am a Chinese too.
One of my recommenders (a Harvard economist) also told me that I should improve my oral English, although my TOEFL and GRE scores are fine.
I think the most important thing that prevent our Chinese from entering a top program is that U.S. professors do not know whether we are really interested in research (savoring the fun of making model, intuitions). If many Chinese guys can be hired by top schools as assistant professors (like UPF, U Tokyo, Bocconi, New Economic School, ITAM, AUEB), not just accepted as graduate students, then it will become easier for our descendants to enter a top ranked program in U.S. Isn't it?