Here is the results of an "experiment": I and a colleague both booked the same LAX-LHR flight on two different PNR's (no way to tell that we knew each other even). I'm a 1 K for over a decade, and 1 MM miler (nearly 2 MM but just under and so lost the RCC for life during the merger by about 4 months of flying); he is a GM with no status and only about 20 K lifetime UA flight miles. I booked my res prior to him, and I went onto the waitlist for upgrade immediately using a GPU. He booked and paid for his ticket one week after I did, on the exact the same flights. My fare basis was V; his was W; my fare was higher than his fare in dollars as well, for the same flights. He requested an upgrade from E to C using miles. In short, I had him "beat" on every single possible published and elite criterion, except that I was using a GPU and he was "paying" with miles.
So what was the outcome?
I checked frequently for R and RN inventory, and although there were initially 20+ C seats available (lie-flat new config 777 in C) one week prior to the flight, C inventory on the seat map started to "disappear". Frequent checks online and using EF by me never revealed R or RN inventory opening up. During the last week prior to the day of the flight, the buy-up amount was over $5000 one-way, so probably not many people did it. 24 hrs prior to departure, there were only 2 seats (!) showing availablility C. EF showed finally (!) one RN availability at somewhat less than 24 hrs prior to departure, and even though I was on the waitlist still, i promptly called, and finally got someone to force the upgrade (even though they said that they were instructed not to do so). I got on the plane the next day, and sure enough, my colleague is sitting right next to me! His upgrade, on miles, from GM status, came through several days prior, without him asking or doing a single thing. I repeat, he is a GM, with no status, on a cheaper fare, in a lower fare class, who booked after me and requested the waitlist for UG after me, and his upgrade cleared automatically and mine did not clear at all (and wouldn't have cleared at all if I hadn't forced the UG when RN became available).
On the return flight, a similar thing happened, except that there were 18 seats showing available one week prior to the flight in C, and they all 'disappeared" from the seat map, becoming assigned as taken, in a two day period. No R or RN inventory ever opened up per EF but the cabin was full, and walking around showed lots of people who had been upgraded on miles and with other instruments and who were of varying status. And E+ inventory two days prior to departure showed 50% load in E+ on the return flight and lots of seats with whole rows empty. But when I boarded the plane, voila, E+ was full (they were offering TOD upgrades to E+ for $89 to all at check-in).
So GPU's apparently are not worth much, except after all possible revenue generating opportunities, including miles, are exhausted, and elites (in my case now 1K formerly GS for 6 years) using GPU's are lower on the totem pole even than GM's for upgrades if they are using GPUs as their upgrade instrument.
So this is why GPU upgrades are so hard (at least in part) to usenow; they are basically useless.
Hello AA or basically anyone else who treats their elites, well, like elites. And who does what their published priority list says they will do.
This is the first time in a decade that I have not upgraded on an intl flight. But it is just a sign of the way that things are going (having lots of problems, like everyone else, on domestic flights of all types as well).
We had a nice thing going with the PMUA. Sorry to see it gone but I don't suspect that post-M UA is in fact really sorry to see so many loyal elites over the years gone now. They are making their own bed and are going to have to lie in it. Very sad.