This was our 4th NCL cruise and the Jade was the best ship to date.
Going in Nov/Dec had pros and cons, it was not crowded anywhere, walked right into the Vatican without reservations, but it was also colder in some ports. Cairo was a beautiful 75F, Paris was snowy, many places cloudy some drizzly. Seas were very smooth except 7-12ft coming/going around Sardinia for some reason.
The DD cabin was a free NCL upgrade from obstructed. It was very nice, not as roomy as some perhaps but still had plenty of storage. My only gripe was no NFL games or TCM on this cruise, lots of ads and news, and a few movies. We also had some bad neighbors that were thankfully kicked out early on. We were above the disembarkation door so there was some noise when they docked. Overall we still loved the cabin and location on the ship was absolutely perfect, stairs/elevators just around the corner, disembarkations one deck down, Alizar one deck up, Garden Cafe elevator up to deck 12.