The last time I flew to SUB was 1.5 years ago on CX. I had booked an H fare/Y class and was offered via e-mail an upgrade to PEY about three or four days before the flight for the humungous amount of £41 so snapped it up and got the TPs and Avios. Unfortunately CX on the HKG-SUB route commands direct flights and whilst looking for an upcoming trip in a few weeks and pricing up PEY for a PEK-SUB flight, prices were coming in at around £2100 so have had to slum it in Y.
I don't know if they still offer the e-mail upgrade offers but if I receive one (here's hoping) I will let you know.
ETA: Do you have OW status? I have had quite a good op-up rate with CX on the HKG-SUB route as OWS/OWE (that's me probably gone and jinxed that now).
Safe & Happy travels
S
Last edited by Saltire74; Feb 18, 2015 at 8:32 am
Reason: Edit to Add