We picked Norwegian because it we'd never sailed with them and decided to give them a try. We'd been on Princess before and were looking to see if we could do better.
This seemed like a great itinerary because we would start in Manhattan; it would only get warmer from there - right?! Turns out you waste 3-4 days because it's just too cold to be outside for too long.
We got to NY the day before our cruise. We loved NY so much that we decided to come back, but only when it's warmer. Just too much to see and do, could not fit it all in.
It was worth it for the bigger deck, shower was EXCELLENT!