T1 Qatar Airways to/from DOH. Enormous terminal long distances to/from gates but all the travelators work so it doesn't matter. Large queues at security/immigration but through in minutes as sufficient staff are available. Excellent selection of shops and restaurants but not easy to find shops which sell bottled drinks (more practical for long-haul flights). Security efficient and firm but polite. Helpful staff everywhere with good English spoken. Cleanest airport I have ever seen. Bag already on the belt as soon as I cleared immigration and on the MTR 30 minutes after landing. In-Town Check-In works perfectly and saves hours. Everything seems to work like clockwork here. HKIA is clearly the Gold Standard by which others ought to be judged - no UK airport even comes close.