My negative views on the QM2 relate more to her interior design, than her hull form or engineering which is solid and conservative. (Hey, I would have liked to have seen her built by H&W but that was too much of a project risk let alone more costly).
As we know, as built, the QE2 was up to the second and far as 1960's interior design and maritime engineering was concerned (did the designers of the Pametrada turbines and Foster Wheeler boilers of the QE2 fully understand how far they were pushing things). She made every ship since 1950 old fashioned, bar the Canberra/Oriana.
Carnival had the chance with the QM2 to make her a statement in early 21st century design by hiring the best UK interior designers and making something really special. But, instead played safe by commissioning Tilberg to execute a 1930's Art Deco revival interior. I understand why Carnival went the way they did, as most passengers are after that "grand 1930's experience" and under that criteria, the QM2 delivers by the truck load.
In many ways she's a "boring" ship. But that's me as a bit of a ship geek talking.