I haven't read through the full thread, so please forgive me if I am repeating previous comments.
One thing I would say is that when it comes to dining, QM2 is a three class ship.
It is dependant on the Suite/Cabin you book which determines where you may dine, and the three classes are very different.
Only 1st class (Queen's Grill Suite) passengers may dine in the Queen's Grill, which has the finest cuisine, best chefs and top silver service waiters.
Then you have 2nd class (Princess Suite) which is still really very good, dining in the Princess Grill.
Then for most of us it is steerage. The MDR's or extra for speciality. The difference between the Grill's and MDR's is like comparing La Bernardin in NYC to Nando's. Oh and don't think you'll get in the Grills without suitable attire, regardless how much you paid for your suite.
They do however do possibly the best afternoon tea at sea, which is inclusive for all, and not to be missed.
Personally I find Cunard a bit stuffy, and I'm used to wearing Tuxedo's and Lounge suits, but I've got to the stage now where NCL are more than good enough for me.