I have flown Air China a number of times without a problem. Now there is usually a layover somewhere before you get to your final destination. If you coming from Australia to China it will probably be direct. If you are flying onward you will have to change planes and wait. I have had 11 hour layover’s getting back here to Bangkok, but stayed at the cheap airport hotel in their hub cities. They were on time, food terrible, seats uncomfortable, and flight attendents were fine. Air China is 21st century and no better or worse than other long haul carriers.
Time of my life is spot on. Why would there be a catch? Air China may not be budget in Airasia terms, but its hardly in Emirates or BA league either so there shouldn’t be any surprise that it is cheaper. Also airlines fluctuate their prices wildly all the time, even the big ones, so if you have found a great deal on a flight snap it up before its gone!