Don't know what the package is at CX but I am sure that you would be paid more as a Captain with KA than a FO with CX and command at CX won't be at least before 10 years when in KA you'll be doing the course within 1 year.
Hope you're really sure you want to come back to HKG, even if you call the place home the city is far from being as good as it used to be.
A lot has already been posted on how expensive, overcrowded, polluted the city is and unfortunately that's all true.