Having left Canada a few years back I will say this.
Although AC is hiring things in Canada are still pretty limited as to what you can do. At 30 now and in a large European company making 2-3 times the salary on the EMB at AC, I would not come home.
Given the choice between AC and CX I think CX would be a no brainier. Financially you and the company are in better situations. The down side is HK for some but from what I can see your time there could be limited if you choose so.
If you like Toronto, baking in the summer and freezing in the winter, high housing prices (I know HK is bad but CX pays), terrible traffic and least but not worst you must live amongst Leaf fans, then AC is for you. For left coasters YVR is a long wait so take CX in my humble opinion.