As a BA Emerald who has now been based in HK for a decade, and having relatively recently started clocking points to Marco Polo instead (still only four months since Gold, but only 35k till Diamond), I can say from extensive personal experience that CX treats CX Golds better than OW Emeralds whether it is in the form of important unofficial benefits such as op-ups as well as less important but nice-to-have unofficial benefits such as personal greetings onboard flights. In fact, the reason why I have switched to Marco Polo from BAEC is precisely because of the better treatment.
As for official benefits such as which check-in desks one can use, or priority boarding, these are pre-agreed across OW so it isn't an option for CX to cut these.
The real issue is that there are all these false Golds / fake Diamonds around who have been granted their status through Amex rather than actual flights miles like us real travellers on this board. I understand the marketing logic of CX offering the Amex deal to potential future customers, but in doing so they have annoyed many of their actual current customers.