Originally Posted by g46r

This is true. However the T+ fare of the ex-USA are similar to AC's fare during same time period last year (SEA-PVG for example, which I fly about 4 times a year), while the Tango fare is about $200 less than T+. Last year all they had was T+.

As long as the above remains true, the introduction of Tango fare simply gives you an option of spending less (and get fewer status miles - and no upgrades).