Typical Chinese ATC clearance: "delay undetermined due flow control". If there was any flow control you would get a departure slot or ETD.
"you wait till all of the jigsaw puzzle pieces are in optimal position before you wiggle the last few into place so you can commit and get it right on your first try"
Very good Arthur but while they are wiggling their pieces we are burning gas at the rate of about 50-100 kgs per minute!
Being stuck 6000-10000ft below optimum level together with the approach controllers obvious confusion as you enter their airspace, cost airlines between 500-1000kg of gas per arrival.
Beijing was ranked 21st busiest airport by movements last year so it is not that busy. I suggest they sent their controllers to the States and Europe for a couple of years and maybe then they would do a better job copying them than most other things they copy.
First rule to fixing a problem you must admit you have one. Unfortunately the Chinese are incapable of that, so don't expect any improvements in the near future.
Arthur, keep smoking what you are smoking and maybe join a teachers' forum.
This is a Forum for AVIATION PROFESSIONALS as the banner at the top clearly states.