PEK, BTW, is the exceptional route. They almost never release any upgrade seats at all, and like SPBanker reported many times, there almost never are any op-ups either. It cleraly is the route where they manage to sell the J cabin.
CKG and BKK is on the other end of the spectra, J cabin normally wide open for upgrades (and later on filled by op-ups).
Last edited by intuition; Sep 7, 2015 at 11:51 am
Reason: BTW = By The Way, not Batu Licin, Indonesia