Cannot believe this system. Flying GVA-VIE-PEK-HRB and of course Austrian Airlines (as it is the first flight of the itinerary) does not let me choose a seat on the CA sectors. It assigned me a middle seat in the last row of business class, despite being booking class D. Air China website requires identification; since the ticket is booked by a travel agent, I cannot check in there. Try to register on their website/app: impossible, error codes without explanation. Called the hotline: they were nice but they cannot access the seat map and simply told to ask at the airport. At GVA I am sure they will say the same: cannot access air china data. And by the time I get to Vienna, the cabin will be full.
Given the price of 7000 EUR for this ticket, this really makes you fly Air China again....
What's wrong with asking at the airport? This is my approach 90% of the time.