This has been a very interesting thread - thanks to the OP for starting it and for all the contributions of experiences.
I guess I had CX pegged wrong - figured they were very conservative and would never consider this type of wheeling and dealing. I guess 'yield management' does translate from English to Cantonese...
Will have to give this a shot on my trips this year. Especially for the LAX -> HKG legs.
http://www.angrybackhand.com