http://www.airlinepilotforums.com/forumdisplay.php?f=4
is the place to go for information.
Some issues raised there:
Age 65 will increase command time
Low housing allowance for HK (2700 USD I think)
No education allowance
Flights are from CAN, with long minibus trip before/ after duty
Consensus is that it is not a good deal, except as getting a toe hold on a big US carrier's seniority list - and that that may well be worth it for most!