I used to fly Hong Kong London Hong Kong once a month with either Cathay or Singapore in business class for to attend board meetings in the Uk. One thing that pisses off business clsss passengers most is when an economy passenger gets a free upgrade due to poor planning by the airline and not as some loyalty reward which is fair enough. It is worse when they have no idea of how to behave lol.

I agree with the comment on Chinese having flown over 100 flights within China they are rude, arrogant and just plain ignorant a lot of the time and that is the business class lot !!