Don't transfer to IB! You will get the least value for your miles.

Comparisons:

BA:

Europe - USA
C = 100k
F = 150k

Europe - China/HKG
C = 160k
F = 240k

CX

CX is done by mileage so here are some examples (red = 1 carrier. blue = 2 or more carriers):

LHR-JFK:
C = 80k
F = 120k
C = 80k
F = 105k

LHR-ORD:
C = 80k
F = 120k
C= 85k
F= 115k

LHR-LAX:
C = 120k
F = 180k
C = 115k
F = 155k

For rewards to China/HKG:

LHR-HKG/China
C = 120k
F = 180k
C = 115k
F = 155k


MH

Since it is not part of *A yet we can't really speculate how good the burning will be. But you may be able to take guesses based upon their own mileage system:

Europe - KUL - HKG/China
C = 102k


To me it looks as though CX is your best choice!