Originally Posted by
robbbbb
F: 40kg. J: 30kg.
Never enforced. I don't believe check-in staff care at ALL about first v. business fare codes.
There is a U/F/MU-Plat section in the Lounge 36 in PVG T1, but of course that's for int'l flights.
Yes, I've been to that lounge, but the OP asked about domestic flights.
Apart from the possibility of earning more miles based on fare class (this applies to all fare classes), there is honestly no difference at all. On 2-class flights, if F is cheaper than J, buy F. If J is cheaper than F, buy J. (I'm using these fare codes to represent first and business, not actual fare codes because those are rarely displayed during booking unless you dig around.)