I would rate Cunard far below these lines. We recently did a cruise on the QM2 and were greatly disappointed. We had a Q4 room which meant we dined in the Queen's Grill. While the food was fine, we were disappointed to discover that the menu in what's supposed to be the gourmet dining room, was the exact menu they served in the huge Britannia restaurant. While there was an ala carte menu in the QG that they don't have in the Brit, we really didn't expect to pay so much money for an upgraded room only to find out that we could have the same food as the much cheaper rooms.
Service on the QM2 was also greatly lacking.