I have flown over 60 segments within China in the last couple of years, mostly on Air China but also on China Southern, Sichuan, Hainan.

Safety generally is not an issue (China Eastern flight downed at Baotou within last month is a notable exception) in my opinion. They seem to not want to fly in conditions where it would be safe here (maybe there radar isn't as good at some of the airports). Worst part of domestic China flights is tight seat pitch. If you are tall, make sure you get an aisle seat or emergency exit row or better yet upgrade to business or first. Cost between Y and C or F is not huge IMO. For 1 hour flights, I can stand the tight seat pitch as long as I have an aisle seat. I dump out the magazines on the floor or my knees will be very tightly pushed into the seat in front just with the thickness of the magazines.

Bin space can be at a premium. I generally check my bag but had it lost for the first time this fall on Hainan with not so pretty service response. They knew where it was but . . .

There is always a crush for boarding so people can get their bin space. Domestic flights are often heavily loaded (ie full). Sit back and enjoy!