Ace and Tax Dude you are both right, I want to use a SWU and pay the difference in fare between my current V-class to M-class.
I understand the details now, I think they should be more flexible and gain another 600-800$ from me. But the system doesn't allow it.
Well row 18 on a 777 from FRA-YUL ain't that bad for this relatively short flight
(I keep my SSWU for all my asian flights)