In fact Oneworld fan, though the service in J and F Class in CX is brilliant (I have experienced it many times thankfully), they do have problems with diction on those flights, especially among the females. For example, I received orange juice, instead of tomato juice.

I have flown Emirates and United Airlines and Singapore Airlines in J Class (F class a few times on the latter) and have experienced no problems whatsoever. Though, obviously in an non-English airline, you're bound to have some difficulties.