I recently returned from a 14 day transatlantic round trip on QM2, a trip that I do each year from, and return to NYC. Getting to the ship at the Brooklyn Cruise Terminal is a bit difficult as the surrounding streets are gridlocked on "ship days", but once you get to the terminal all is wonderful.
Embarkation quick and easy, walk aboard to your cabin where your dining assignment card awaits, to King's Court Buffet for lunch, early and prompt baggage delivery, a quick and easy embarcation drill, and you are on your way. I had a "glass balcony" cabin at same price as an outside without balcony as a result of a price promotion.
First night is "elegant casual (coats for men, no tie required), all other nights but one will be "formal" (and they mean it), with one semi-formal (suits OK) in the middle of the week long crossing, with another elegant casual night on the last night.