My experience with Air China is unfortunately limited to International (as well as China domestic) First and Business Class, and walking through the Coach cabin to stretch my legs on a few occasions.

Regarding food, I think there are high points as well as low for First and Business class, and I would rate them a C+/B-, may be B-/B if I am really generous. I have not had an opportunity to try Air China's coach meal, and therefore could not comment.

The coach seat on the A340-300 is probably very average in pitch, around 31 inches, I think selecting the pairs of seats along the fuselage (perhaps an aisle of the pair) would be the best choice, especially toward the front part of the coach cabin.

As for service, as I mentioned in a couple other threads, I was very pleasantly surprised by Air China. Actually service was much better than I expected, certainly equals the North American carriers, and a small step behind the better Asian carriers, and a more of a stretch to reach the likes of SQ.

An example of service: On one occasion, I was on a domestic PVG-PEK flight, connecting to PEK-YVR with a tight connection. The PVG-PEK flight was unfortunately allocated a remote parking stand, and there were a number of passengers in F and Y, both foreigner and Chinese nationals whom could be affected by the delay.

I was in the F cabin, and overheard the conversation of the cabin crew, with the ground service staff, and their walkie-talkie conversation with the staff arranging the transfer bus. During this about 20-minutes delay, all the conversation I heard was the concern for the well-being of the transferring passengers, and attempts to mitigate the delay, such as figuring out the order of loading passengers into the transfer buses, directions to provide, notifying the luggage handlers to expedite transfer of bags, re-arranging the priority of transfer buses from other planes to ours, ...etc. It seems to me that the staff really do care, and did not think their duty ended when the aircraft door opened at the remote stand, but rather, truly want to hand the passengers off to the best extend possible. It also does not appear that they were acting for my benefit, as I was seated in my F seat, and overhead the conversations as the staff were congregated near the opened L1 door with the air-stair attached.

I ended up on one of the transfer buses talking to two Americans returning to Atlanta, they were in Coach on the flight, and they had a pretty good impression of the staff as well, and even compared the service to Delta's southern hospitality that there are accustomed to.

I am not affiliated with Air China, just a very satisfied customer with what some might say extraordinary luck with their service. On my first flight with Air China, I thought the positive things were just a statistical aberration, and figured that everything would probably average out. After quite a few more segments with Air China, I am still surprised that my batting average is still high. Perhaps over the much longer run, things would really average out.