After my PC crashed once done w my post - here my 2cts again:

my personal rule of thumb:
PEK to PVG more likely to be international metal w international C/F (esp 3-class config). Ensure you have a feeder flight OUT of China so any delay on the international lag INTO China does not force you to delay (esp as there are not so may flights to PVG)

PEK to SHA is mostly domestic C / F. Certainly not the same standard.

Go for 3-class planes if you aim for C (good value) or F (if you insist on luxury).

There is no discount on C / F if ticket is purchased locally.
Do not purchase domestic tickets overseas. Use elong or ctrip if you don't have anyone in China who can book them for you. both provider are also good information providers for flight info on your dates. They have international call centers and I believe they now accept intl credit cards.

I personally prefer the new Terminal 3 in PEK (FM and CA is using it). MU is using the old lousy Terminal 2.
In addition MU is arriving at the old lousy terminal 1 in PVG. FM and CA the new Terminal 2.
Not sure about SHA (Rarely use it as it is so overcrowded and further away from my office location in Shanghai).
*Alliance lounges in PEK T3 are quite good IMHO.

I also avoid the food in any domestic class. In F I do eat the fruit

Also consider milage accrual impact on Y/C/F ticket. C/F is a marginal upmark to full fare Y. Depending on your milage program you can earn double status milage in C. It goes up to tripple in F. Towards end of the year this could tip you above the renewal amount. Compare FM vs. CA if you are in Star Alliance programs. Lufthansa Miles & More is giving more status miles for CA (compared to FM).

Regards
Ham