The trick of my $200, 30,000 US AIR Miles ticket was that all flights must be on Air China metal. I've flown Air China many times and for the most part have not been impressed. I was excited that this flight was on an A321 versus the standard 737. Perhaps this would make the flight different.
I've flown Air China business many times. It is underrated. As part of the ANA RTW ticket, I maximized my 22k miles in business by adding the final Chengdu to Kathmandu segment.