After 2 cruises with Princess, we decided to try Norwegian based on the port that it departed from (New Orleans). Overall, I will say that we (and several others we talked to on the cruise) prefer Princess in every category.
Some positives first: When visiting Roatan, Honduras, you MUST do the Maya Key Private Island excursion. This was by far our favorite stop on the cruise, and we would have been happy to spend several days on the private island!! The beach, snorkeling, animal rescue sanctuary, and picture spots were only some of the amazing things we experienced - and the buffet-style lunch was delicious! Onboard, we really enjoyed the "Elements" show on the last night of the cruise and the great deals on 3-liter bottles in the liquor shop (we bought them as bar decorations :) ). Eating at Cagney's Steakhouse is another MUST - delicious food with great selections! Our stateroom steward was wonderful, and we liked the "self-disembarkation" option that let us carry our own bags off of the boat. Though there weren't formal nights onboard, photographers were set up every night to take pictures, so you could dress up any time (we enjoyed this!) and take photos.
In Costa Maya, we got a taxi to the "downtown" area and enjoyed time on the beach and a $25 hour-long massage. Be warned, though - they "don't have change" so carry many small bills so that you don't end up leaving a huge tip, and there will be people trying to sell you something all the time (this got very annoying after several hours)! I would recommend going back to the boat or dock area for lunch. Belize: Altun Ha ruins and Olde Belize River tour was just ok. A VERY long shore excursion, and the lunch we were served wasn't great. I wouldn't recommend this excursion, but Bacab Jungle Park (where we had lunch) looked nice and enjoyable with its pools and lounge area.
Adjoining room = can hear EVERY sound in next room! :( Good size closet, nice size window. Deck 5 is very bad because you're so low in the ship you feel every rocking motion, and this room is at the front of the ship (=long walk to the main areas).