One thing I've seen a lot of at various flying schools that deal with international students is instructors that lack experience/aptitude blaming the students for various things. Laziness, racial and cultural background, lil emporers etc... Generally it comes from teachers that have one set of tricks and if the student can't understand then it must be something wrong with them. The only real problem is the barrier of English comprehension, once you have a bridge for that you just adjust your techniques for the individuals personality. There will always be some that excel and others that fall behind but that has nothing to do with their race, creed or culture.
I have found the majority of Chinese students to be very hard working and intelligent individuals that can work together to achieve. The biggest problem is miss-understanding of instructions due to language, they may carry the wrong idea for hours of training due to this and it can be frustrating.
Of course there is always a few students of any background that are hard work and need to be pushed to achieve or persuaded to find other lines of work.