I have been passenger on Air china and China Eastern from Chengdu to Xian and back using MD80 and Airbus A320. On a later date from Chengdu to Lhasa and back using A320 and B757.
On all occasions I had the same impression as Fareastdriver and was pleasantly surprised. On one occasion I met with the cockpitcrew, but they did not seem to understand english, which may explain the lack of information from the cockpit.