Here's my thinking on each:
_WJ:
pros
-possibility to move to YYC in the next few years as GTA is just unaffordable
-better income and pension (for now)
-socialized bidding very interesting to me as I'll be bottom 50% for all my career
cons
-won't see left seat before 10-15 years
-B737 for all the career!?

_Transat:
pros
-better quality of life and long haul flights
-Airbus

cons
-stuck in YYZ because neither me nor my wife speak french
-future of the company a bit uncertain?

Please feel free to share your opinion. Thanks!
