Maybe because we have been sailing with Cunard since early 1980's and in Diamond Cat., we don't get emails from Cunard for Upgrades or bidding.
We have always received comp upgrades to the next level. Never got phone calls from Cunard.
We get comp's to PG and once on the QE2 we went to QG even at the Pier Desk.
We just book what we would like, anticipate arriving at that cabin we booked and look forward to enjoy. If the Comp Upgrade Fairy visits, we appreciate the offer and enjoy. We've got about 6 comp offers in the 12 years.
So we just book, wait and arrive as we expect.