I've followed this debate with interest over the past months. I think that the number of people who can make the switch are limited to those who mainly fly trans-border and who are living near a main hub well serviced by US airlines. I don't fall into either category.
The rest of us don't have a lot of choice unless we are willing to fly out of our way to use US carriers.
For TPAC and TATL travel (which is mostly what I do now) AC is still my best option as I like the lie flat bed option and as an SE I get upgrades 95% of the time on Flex Fairs.
I suspect a good number of FTers are in the same boat as me and making many of the same calculations.