Returning to the subject of upgrades, I wonder if last minute upgrades at the gate are disadvantageous. Qualiflyer sells upgrades on a one-way basis only, and that over a miximum of 2 sectors. I am not sure that, if you upgrade at the gate (or check-in; both are last minute), you can upgrade over the two sectors. So if you were going from Lisbon to Hong Kong, you would probably have to upgrade at both stages, paying separately (with miles).