I have just returned from a crossing on the new QM2. The ship itself is absolutely spectacular. much more like old Queen Mary than any other modern cruise ship. Sadly to sail in this spectacular setting you must put up with mediocre food and mostly poor service.
The Brittania Dining Room menus were designed more for European than American taste. There was only one truly enjoyable dinner in six nights aboard. The dining room service was the worst I have ever seen in 33 years of cruising. The casual dining rooms are chopped up into 4 small areas with the serving areas far apart and inadequate seating for a full ship.
The ship had a high percentage of British, rude French, and German passengers so the smell of smoke hits you the minute you board the ship. The incredibly beautiful Chart Room was so smoky in the evenings that I could not sit in it. Only in the lovely Commodore Room with two distinct halfs could you enjoy a cocktail in a relatively smoke free environment.
On a positive note, the lecture series was excellent and a highlight of the crossing. Sadly the evening shows were typical cruise ship dreck just on a larger stage.
The embarkation process was incredibly smooth, the debarkation the exact opposite. I am glad I experienced the QM2, just for the ship itself, but have no desire to return.