Originally Posted by
flyingmusicianlax
... Don't you get space available instant upgrades if purchasing full fare?
It's not an instant upgrade, you get put in the upgrade queue, albeit ahead of other people waitlisted for upgrades.
The earlier you request your upgrade, the better. Upgrade requests are prioritized based on your elite level.
Within each elite level, full-fare Economy Class tickets booked in Y or B are confirmed first, followed by all other fares, in the order in which the upgrade request was received.
So, an EXP on a QSONG fare will get upgraded ahead of a Platinum on a Y fare. And I'm not really complaining about that - I do okay on upgrades. If I wanted to fly F every flight, I'd buy F every flight.
My deal breaker would be
a lack of MCE availability. DL and UA, for all their other faults, have their fleets configured with substantial Economy Plus and Economy Comfort cabins.