First off, the Queen Mary 2 is an ocean liner and not a cruise ship. The overall experience reflects this distinction.
The dress code for passengers helps to create a sense of occasion. It felt like you were doing something special as opposed to casual cruise where it feels like you're on an ocean-going Walmart.
There were many little touches by the crew which added significantly to overall experience. The ship's deck officers were personable and friendly.
The cabin was very nice and the balcony was huge. The balcony of our cabin was easily 4 times the size of our balcony in The Haven of the Norwegian Breakaway.
There were many things to do and see withing walking distance of the ship.
They provided a free shuttle bus from the dock to Boston's North End and there were many, easy to walk to attractions in the area.
Boston's 4th of July fireworks which were HEAVILY touted in the brochure, were barely visible from the ship. You could only see a little bit above the Boston Skyline. It was reminiscent of the "being attacked by Hottentots" scene in Mary Poppins.