Originally Posted by
5khours
So a question, and I would really like to know the answer. Assuming I am buying M fares typically about 2 weeks out and have not much flexibility on dates, would I be 100% certain of always being able to get an upgrade using miles or SWUs on DL.
With Delta, I will not buy the M+ fare unless there is Z availability at the time of purchase. I find that there usually is, although I sometimes have to fly through an airport I don't care for (like JFK). The advance upgrade availability is probably better on Delta precisely because they do not allow for upgrades on the cheap fares.
FYI, if I have to fly longhaul coach, I won't fly.