Actually, in my opinion, not sure about reward seat availability, but in general CX is probably one of the better of the oneworld carriers when it comes to treating its top-tier OW members that aren't MPO. I'm an MPO Gold member residing in New York, so often for my domestic flights and my one flight a year to ZRH I use AA (vs. BA for mileage purposes in Y). However, when I spoke with AAdvantage last time and asked if top-tier non AAdvantage OW members are considered for complimentary upgrades at check-in, they said that that's reserved only for their own members and those with 500-mile upgrade coupons (which are also given only to their own members). CX on the other hand does upgrade OW Emerald members of its partners on CX flights and doesn't reserve that only for their own. My last flight to ZRH actually, J was empty but Y was packed, yet I wasn't even considered for an upgrade, seeing as how I was still in Y a few rows from the J cabin. So really, I think its an issue across oneworld how each carrier treats members from partner carriers and not only a CX business practice. Honestly I agree with you, but a carrier is going to reserve some perks for its own.