David, you're right, there isn't the intimacy of a small ship and the relationships with the staff. There were, of course, some exceptions, particularly the staff who were drawn to the baby in King's Court.
Most of the time the ship didn't feel crowded. There were a few exceptions. Sometimes we had to look for a couple of minutes for a table in the Queens room for afternoon tea.
For us, being able to go over to Europe with the baby not cooped up in a tin can was a major plus. The return flight from London was really hard and we were in biz. And, of course, the British nannies gave us some time to ourselves and Madeleine got to play with other kids and do fun activities.
In all fairness, the Queen Mary is not a mass market line, it's a hybrid between mass market and luxury. The per diem rate is definitely higher than Celebrity or Princess. But they had lots of the touches that luxury cruises do like complimentary shuttles into town all day and laundrettes on board with free machines and detergent. The signing for drinks didn't bug me too much and we did the auto-tip so we didn't have to deal with individual tipping.
We had to move cabin between B2B and they moved all our stuff for us. From my own research, I don't think they have good single supplements. A friend was going to join us but they would have had to pay 100% single supplemement.