About to fly with SK via Seattle, and it is a bit longer then the other Sas ,US routes, I´m thinking about upgrading from V class, to at least Y+, however I have been quite lucky last times on SK to US with upgrades to EWR. However I have never flown SEA route...anyone with some info how the load factor usually is on this flight, will fly out 5th March, and it looks quite open in all classes..