Agree so much with moondog on this.

We maintain Air Canada Elite which really helps when we have to move again in a few years. Many times, we have a choice of carriers and Air China is almost always more expensive than the other guys. (Double or triple in price if you compare it to Juneyao or Spring Airline fares but I already have ranted how unreliable they have been.) From a scheduling perspective, we found Shanghai Air and China Eastern to be so much more convienent but we end up taking Air China to maintain status.

It pays off with the luggage weight restrictions. Especially if you fly economy. If you are flying in F on a full fare then you get three pieces of luggage at 23 kg if you want without extra charge. (not that I have needed it, I physically won't be able to carry that much weight plus my wife's stuff)