I had my time in Asia and I remember the difficult to understand Chinese Pilots and Controllers. Cambodian, Vietnamese and Korean where also part of the say again phrase. Out of the ordinary was difficult to sell.
It was always exciting to listen at busy Airports like LAX, JFK, LHR or FRA how some certain Pilots-Controller conversations developed stress in the Cockpit and wonder if they get it on the screens.
I remember also about 10 years ago into PEK the clearence to descent to 2.000 m and 3.000 m was diffult to understand back then. Say again made the Man on the Ground angry and his voice was raised and it was even more difficult to get the diffrence out of the Jinglish, the last few years it got better as there are more Airlines from all over the World heading for PUD and PEK and the basic got better but is still far from that was HKG has to offer.