Perhaps posing these questions now is slightly too early, and many are not yet settled on an answer, but with the
changes to the MileagePlus program in 2020:
Will you change to or favour another airline loyalty program?
What program(s) do you find to be better going forward?
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My own perspective now is mainly uncertainty.
I do virtually all of my travel planning, and also virtually all of my travel spending comes out of my own budget or income. I feel the program has rapidly become too expensive relative to the cost. Without finding a special niche or loophole, the cost of 1K status has gone up $6k in two years. I think that is simply too much. Over those two years the ability to upgrade long-haul flights has not improved, and at least to me that was the main value in the loyalty program. Most domestic benefits — short haul CPU, snackbox/burger, even E+ — are to me worth tens of dollars per flight, i.e. not much. I usually can be flexible with schedule to make it work, but it's tiresome doing that every trip.
For the questions above, I am suspecting I may switch to having no focus on any program, but I have not done a thorough analysis yet to know everything that is out there. The Star Alliance network has been well suited to my travel, but I also have relatively limited experience with Oneworld and SkyTeam. I'm sure DL and AA are not going to be any more appealing than UA next year, but perhaps a foreign program will be. So as to the questions —
Will you change to or favour another airline loyalty program?
Subject to change in my thinking, I will primarily fly UA in 2020 with status benefits, and thereafter begin splitting credit between something in *A and something in SkyTeam or Oneworld for low/mid tier status in both.
What program(s) do you find to be better going forward?
Unsure at the moment.
The only thing I am sure of now is I will not be handing over 18k to UA next year!