Sleeper passengers are generally the better off class and are reasonably behaved. However with the introduction of high speed trains a lot of loco-hauled trains (including overnight trains with sleepers) have been withdrawn, forcing everyone to pay more for the speed that they don't necessarily want (and possibly forcing them to travel a few hours in daytime as opposed to overnight). Operation is usually smooth except when it's not. I can understand if it was due to weather conditions, but as with other socialist countries, the government officials prefer to travel in their dedicated trains (like a moving hotel) and all scheduled trains in vicinity have to be pulled into loops so the special can overtake. Depending on the level of the official, trains in the opposite direction might also be required to stop so if any passenger threw rubbish out of the train windows won't scare the official. Just like when the prince family visited Sth Melb. Beach all regular trams were shunted at Park & Clarendon Sts but can you imagine doing it with trains that have about 1200 people booked on each of them?
China frequently closes air space at zero notice for military exercises. We boarded a place once, pushed back, then pushed back to terminal and had to wait 90min.
The rise of the middle class has seen millions of people who have limited social behavior standards such as how to line up suddenly released to the world's travel industry and with it a rise in anti-social behavior on international flights and at some high profile tourist destinations. I have been told to give HK Disney a miss due to the high number of rude Chinese tourists, you cannot even relax in a queue without having someone trying to sneak past at every opportunity. In the west we have old mate weighing in at 150kg and/or Karen's to keep the F-wits of the world in check. As a result China has been running travel education classes for its people.
However flying in China, mostly BC I didn't have too many issues and didn't use the HSR. I did love the security scanning process at the airport when you get padded down, usually by a hot 20 something woman who makes you stand on the step (as per procedure) despite the fact she is 5 foot nothing and I'm 192 cm (6'4"). Then they are jumping up to pat down everything from my chest up. Only once did I have a tall one who actually said laughingly at seeing my height, you don't' stand there, too tall, over here.
Similar issues from India middle class, however Indian's don't tend to travel globally in tour group and usually conform to local standards very quickly. However in India, all bets are off but personal experience is that they will often go out of their way to make sure foreigners (read White people) are ok and you will quickly have 1000 Indian's all telling you independently where to line up and for their brothers queue jumping in the Foreigner's Queue to quickly F-off.