It seems like Asia Miles (CX) is a better program than AAdvantage if most of your travel is international. Especially given, Asia mile upgrade awards can be used be used for multiple airlines as long as one segment is with CX.

On AA I alway give up a leg on VIPs for code share and I can't use AA mile to upgrade on CX even if one segment is AA.

Please provide feedback on switching to CX as primary OW carrier; +/-.

Thanks!

because I am not too familiar with AA's program, i am leaving the issues of mileage accrual to others. Suffice it to say that non-airline mileage accrual on Asiamiles is mostly limited to offers in Hong Kong, and very few offers in other Asian countries.

If a lot of your travel is on CX, then the MPC is worth it, no doubt. However, anecdotal evience suggests that AA elites get treated better on CX than MPC elites on AA. (bit a of a David and Goliath going on there). Upgrades on CX are common for top tier members on full flights, where the pecking order decides who gets to fly up front. Every airline gives priority to their members.

Facit: Switching to Asiamiles as a mileage program is probably pointless unless you live in Asia. Joinging Asiamiles (and not MPC) will not yield any benefits whatsoever. The elite program of CX is MPC, not Asiamiles.
Switching to MPC is a good choice if you travel a lot on Cathay and value upgrades highly (which seems to be your sole concern anyway )

There are some discussion before.

One big drawback is no tier bonus for even top tier members.
AA EXP(OW Emerald) earn 100%(?) bonus for your flight.
Unfortunately, CX Marco Polo does not provide this type of bonus.

From some point of view, guarantee seat service for Diamond/Gold member
is great. this benefit is applicable for even discount economy class
(Booking class B/H/K/L/M/V) of CX flight.

Also - Asiamiles expire after 3 years. Retaining miles possible - but expensive.

I am a member of both, and prefer AA more. When I don't get AA credit from a CX flight, I put it on CX. But I like the bonuses, and the non-exp miles of AA.

This is an interesting statement. Can you provide any evidence from T&Cs to support it? The award chart here: http://www.asiamiles.com/am/1,,83101_82763_eng,00.html says that round-trip upgrades are available on BA, AA, CX, KA; one-way upgrades on CX only.

If, for example I have part of a OW RTW ticket which goes HKG-(X)LHR-CAI with the HKG-LHR on CX and the LHR-CAI on BA, are you suggesting that you could upgrade both of those legs with a single upgrade award? If so, how many miles do you think it would cost from business to first, given the award chart here: http://www.asiamiles.com/am/1,,83101_82761_eng,00.html ?

my anecdotal, well, actually i was told by one AA agent,
that they DO NOT care about elite of any other airline, except obliged by the oneworld terms.
i.e. other than lounge access/etc. not discretion will be given to CX (or BA) elite at all, eg priority waitlist, etc.

any one care to give me any counter example anecdote?

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on the other hand, despite the official rule of upgrading CX elite first, we often heard AA GOLD got upgraded on CX flights. whether all MPO were opup'ed already we do not know
but as for myself, as aa explt never really got up'ed by CX (but op-up was often on Y flights as CX diamond, never for J to F)
so these remains to be anetdotes....at least for me

AA have op-up'd me as a QF Gold (OR Sapphire), always allowed me priority boarding, booking seats reserved for elites, and priority checkin.

Unless one flies CX a lot, I really don't see any benefits of switching from AAdvantage.