Upgrade at the airport is stressful takes a long time though.
Did it twice in October, and it takes about 30 to 45 minutes. You have to stand there waiting while they call multiple calls and type on the computer.
Nothing like upgrading with a modern up to date airline like UA, LH or SK.
Also for the doh to lhr flight they said there was only 5 C seats left and the first priority is anyone upgrading with cash, so they wouldn't release the seats for milage upgrades until 1 hour before the flight departure time. I find that a bad way of treating gold members that have earned miles with their airline.