Our previous two cruises were both with Celebrity so it is in this context that I comment on our QM2 experience. First the good points:
Our cabin even though it was a 'port-hole' class on Deck 6 near the bow was excellent and I couldn't fault it. Our steward was quite shy and retiring; he did the job but we saw little of him. The beautiful Art Deco theatre called Illuminations was excellent and had a superb Planetarium feature. The gym, once we found it, was very good. I say 'once we found it' as the various direction signs and listings didn't mention that it existed. The Ballroom and the teas served there in the afternoon was excellent and the evening dancing and band was very good.The shows in the main Royal Court Theatre were generally good; in particular the acrobatic duo. The session speakers were mostly good and the Jackie Stewart talks were excellent. Service from staff was generally efficient. The main restaurant, The Britannia, was very attractive with excellent decor.
Now, the downside:
I guess food is what we would be most critical of. It was no-where near up to the standard of Celebrity cruise dining. The food in the Britannia restaurant was mostly bland with very poor sauces. Sometimes portion sizes were small and our waiters served us extra vegetable dishes to make up. The on-board chefs seem to have little understanding of sauces and flavouring. Other reviewers have mentioned cost-cutbacks but herbs and spices cost little so there really is no excuse on a top cruise line. The selection of food in the Kings Court self-service restaurant was only average. Hygiene control in the Kings Court was very poor with staff not attempting to make visitors use the hand-cleansers. Again you would not have been able to do this with Celebrity and I understand QM2 had had some norovirus a few weeks before our cruise? Service from staff in the restaurants and elsewhere was efficient but the staff appeared a bit cowed. We felt that the crew were quite aloof and did not mix with lower level staff or passengers in the way we had seen on our previous cruises where the crew generally ate with the passengers. Drinks were expensive and wine pricing in particular was silly. On the other hand there was good British Real Ale and with almost normal UK bar prices; spirits were reasonable and sometimes cheaper than the average wine. The speciality restaurant, Todds, had good, flavoursome food but portion sizes were a bit on the small side.
The ships' decor varies in an almost random way around the ship; sometimes it's just a mess occasionally very good. The main Royal Court Theatre is well equipped and comfortable but the seating upstairs is bizarre in it's layout. Off-shore trips varied in cost and value. The arrangements for gathering before dis-embarking were not ideal with everyone meeting in the main theatre resulting in queuing. As someone else has mentioned in another review, arrangements for the final dis-embarkation morning were not followed by the crew and you had to largely use common sense. The promenade deck 7 was the place to get some outside exercise but sadly there was a constant smell at the rear of the ship so you needed to move fast through that part!
In summary, we talked to other passengers who had travelled with Cunard before and/or other cruise lines. Many felt that Cunard could try harder bearing in mind the Cunard branding and some said that QE and Victoria ships were superior.