Chinese food is extremely diverse. Ranging from stuff that is very acceptable to even the most timid of Western stomachs (think the classic scrambled eggs and tomato) through to stuff that even the toughest Western stomach will find 'difficult' (pigs feet anyone?).
And then you get the simply weird (to the Western mind at least) - dog, cat, snake, turtle, etc.
Overall it's difficult to eat badly in China. Even the average street restaurant produces good food.
The best way to get a good meal is undoubtedly to go for dinner with some Chinese - most Westerners get a bit lost when confronted with a full menu, hence we'll be on Beijing Duck again. There'll inevitably be some dish or other on the table that really isn't to your taste - but there'll be plenty of good stuff as well.
The stereotype of the Western tour group heading to a buffet is true to a degree, but we should remember that it's not because the participants are Western, it's because it's a group. Chinese tour groups and big meetings often end up with the buffet option as well. It's the easiest way to cater to a large group.