Which rating would he get ? A Cathay P2X rating isn't much good outside HKG and S/O time doesn't really count. A proper type rating on an A320 with SAA and F/O time would make him much more employable. At the moment neither airline is a good long term option but without children and having a working partner, HKG might be possible for a few years. Time to upgrade to F/O might be reduced as well if CX pilots start jumping ship in increasing numbers.
Realistically, either option would be a transient step before moving on.