Ok, I regularly fly to China and will comment on the options between here and Beijing. As they are private trips, I am price sensitive. There are no direct flights between Zurich and Beijing, so I tried out pretty much all alternatives:

Air France (over Paris CDG): Worst flight ever! Never ever again: A really run down 747, from the four toilets, one did not work from the start, two more break down during the flight leaving a booked out economy class with one toilet... "entertainment" was limited to a couple of old, small CRT TVs that were so old, that each showed the movie in a different color, but never with all. The one next to me showed the movie in a nearly monochrome red. I could keep on about the expected friendlyness of French service personell, but I will only say: Just do not try it yourself.

KLM (over Amsterdam): Not recommended. Our first leg (Stuttgart-Amsterdam) was first delayed and finally cancelled. Not for technical reasons, but obviously financial ones. We therefore did not manage to get out flight to China and had to "hope" that we would be allowed to board the next one. The KLM staff in Stuttgart refused to book us on it and was generally extremely unhelpful. Waiting for four hours got us two vouchers for buying food, unfortunately, they were so low that I had to pay extra to get a beer... I know I bought cheap tickets, but I am still a customer. The plane to China we finally got on hours later was a code share with China Southern, so we could just as well book through them, would probably be cheaper.

Air China (over Frankfurt): the default choice we made the last years: Cheap, decent planes, decent food and the best: Knowing that the guy next to you actually bought a Lufthansa ticket and paid easily twice as much as you is priceless.

FinAir (over Helsinki): FinAir seems to have a new strategy and are increasing their offer to all types of destinations in the far East for very competitive prices. We used them this year and it worked very well: The plane was modern and well equipped, transfers worked well. We will fly with them again. (On the way back from Helsinki to here, they screwed up the seating set-up and the flight got delayed to get a technician to come and turn the last business class lines back into economy (from two seats into three), but I guess that is a minor thing...)