I've done a QM2 transatlantic crossing every year since 2006 and have seen a variety of changes, but the ship is still a true ship in every way.
Cabin: I always tend to book insides. Since the refit, these cabin appear brighter due to what I believe to be better bulbs ( compact fluorescent). The new carpets were actually very plush and though their style is rather unfitting, it grew on me over the voyage. Bathroom is standard, but has a good bit of functionality considering its size. I put in a recommendation to Cunard to restore the interactive TV, which I'll wait to see. Overall, a great place to end the day.
Dining: I enjoyed many meals, most being from the Britannia. It's a delightful well appointed room with great sea views, therefore good lighting. Many spaces on board are enormous and inviting. Having said that,King's Court, the buffet, was never a good place to hang around. I don't complain too much about it, but Cunard is long overdue for a decor refit, at least. I did sample two alternative dining venues ($10) La Piazza serving Italian and the Chef's Galley serving a classic, accessible French menu. Both were worth it! The pub was also a no-miss.Overall, dining was consistently delicious across all venues.
Entertainment: There was always something. For those used to ports every day, a transatlantic may be a neat change or an awkward trip. The whole point of an extended sea voyage on a true liner is to sit yourself down and enjoy a book and deck chair. For enrichment, Cunard is truly on top in the industry. Music recitals, plays by RADA, spectacular 3D movies and a handful of other activities ranging from standard cruise events (Bridge and bingo were packed, but I don't partake to begin with) to odd, one and only events like Champagne afternoon tea. (very nice)
Service was great all over. My cabin steward was Analisa, who was always very cheery and greeted me by name every day. Norman and Noel were diligent waiters who always anticipated my dinner requests, offering to end each meal with a cappuccino.
The transatlantic is THE trip if you wish to really take a classy, dignified vacation.