I have found a lot of the negative comment to be from those in the least-costly cabins, expecting far more than promised. Take the usual grain of salt when you read these posts. No line is going to say let's go to sea and be shabby and do badly, let's not give passengers value for their money.
Having said that, how did you find the QM2? She is new and plastic. There is not really a great sense of England nor the sea about her. Yet the Princess Grill is (for me) good value. Still, any equipment now running for Carnival-Holland America-Princess-Costa (read new-build) could be called a Queen Something and run as a flagship and in time the once-QM2 would be just another ship.
The QE2 is, now, not just another ship. Being on her will be a far different experience from QM2. She is old, smaller in feel and passenger load (by 1,000 people easily). You will know the ship has been sailing long and has seen much. Ports? Perhaps half you will need to tender to. As you are used to a small grill experience from QM2 (what, under 200 dining? rather than the industrial 1,600 all at once in Britannia), you may well love the QE2 Princess Grill. It is the original grill, designed to be a room for dining at sea. My only complaint is that the original cabin-feed into it has all changed, what with the adding of the verandas up on the superstructure. Many cabins now feed into the Queens Grill, a room down in a well, with no ocean views, but still a nice-enough room.........my special beef being that the original One Deck
First Class cabins, 11 each side, the large oval windows, all now feed into Queens Grill. I've been told some will buy Q3, like my favorite 1049, and request Princess dining. You get the best of both worlds, an original First Class cabin and Princess Grill. Even a 450 or so room dining, the single-seating Caronia, the original First Class Columbia room, can be fine.
The ship will not run years longer. Many go on her now while there is still time. I think you and your wife could consider a voyage. It will be unique. You may grow to love her and miss her when she is gone.
Caronia