HKG is becoming unviable as a transit hub due to airspace restrictions by China and the large amounts of traffic in and out of HKG and the other Pearl River Delta airports. Unless there is drastic airspace reform, the third runway won't help and besides, they will close one of the existing ones for major re-work after it opens, so I'm told.
I have been there a long time and the delays are just getting worse and worse. The place is a shambles in bad weather, which is common during its summer months.