Flew with Hainan Airlines several times and now I understand why it is worth flying in their business class: even the flight time is only 1 1/2 to 2 hours, it takes around 35 minutes until they are able to open their door and let passengers out. I mean it is better than China Eastern Airlines, and China Southern for sure, but still, I rather don't get any in-flight-entertainment and the crew can open the door on time. (it happened several times!)