Originally Posted by
zorn
If the OP is primarily interested in return date flexibility, Tango+ would be the best buy (assuming he doesn't change the return date more than 30 times!).
I agree; of course loads vary, but I've changed PEK-YYZ and PVG-YYZ T+ reservations at the last minute many times and have often had to pay only the $50. IIRC, the most I've ever had to pay was around $300 in fare difference, far less than the difference between T+ and Lat.
Also, I've bought Lat fares on the return leg only a few times, precisely so that I can ensure an upgrade. Depending on what is waiting for me back at the office, this is sometimes worth it.