MPC or AS
 

Hi,

I noticed that the CX booking site automatically changes my FFP from my AS to my MPC #. I booked the tickets and added my AS # but it changed to MPC # when it detected my account.

Any disadvantage to using my AS # instead? I mostly fly AS metal so miles there is worth a lot more to me.

The two itinerary I have coming up on CX is SEA-HKG and HKG-CHC in PE. I also have the returns from CHC to SEA, but those are already in J.
Was reading the upgrade wiki thread and it doesn't seem likely that there will be any free upgrades on either routes since they are pretty empty flights it seem.

Thanks.