All my BIS miles have been flown on CX, but my FF program is AA, Why?

I travel YYZ-HKG and then some regional travel (currently in HKG heading to CGK in a few days), virtually all on CX. So why do I collect AA points?

As a Canadian I can have an AA points VISA through a Canadian bank and collect extra points that way.Leisure travel will often be in North America and I can fly AA and use the upgrades I get to fly J or F as available.

Having made EXP(OW Emerald) I get 1st class check in and 1st class lounge access no matter what clas I am flying in. If I am booking an award seat or have some domestic travel issues I have access to the AA EXP desk where the AAngels ae great.

What do I miss out on: being able to upgrade on points, possibly some op ups and having to pay a fee for membership in the club.

On balance, I think I made a correct to join AA, however I would be interested to hear others opinions. I do 4-5 YYZ - HKG flights per year in J and a similar amount of regional travel in a combination of Y & J (that is usually one or two regional flghts for each long haul). Based on that pattern what would be my Marco Polo club situation.