My husband and I have been on Carnival Liberty before this cruise and we really enjoyed that cruise, so I am going to give you my review by comparing ships.
The New York Port was easily accessible, porters ready to take your bag and embarkation was smooth and on time. (We were there early, between 10 and 10:30 and they started boarding right at 12 like promised) The Gem was very nicely decorated. The food in our opinion was very good and much better than Carnival. The entertainment was of better quality than Carnival. The pools were much bigger and there were 4 jacuzzi's. Also, there were 4 full sized bowling lanes ($5 a game), a full size basketball court doubling as tennis court, a rock climbing wall, a jogging track, and a golf net where you could practice your swing. There were also very cool round 2 seater lounge chairs on upper decks and the pool deck had great seating accomodations as well.
Our cabin stewards Loey and Henry were awesome. Although our room wasn't spotless (meaning: floors weren't vaccumed every day, and they missed wiping the coffee table off once or twice) they were still great! Friendly gentlemen who would do whatever you asked. Plus I liked the famous towel animals.(I prefer friendly customer service to emaculate cleaning.)
The ports were ok. Coco beach was like going to our own Ocean City, NJ beaches. Cab fare was $10 each way.
The private island was my favorite! The water was beautiful, the big giant raft rental was worth every penny of the $26, we literally just floated around the whole 4 hours we were out there. (I highly recommend renting or bringing flippers though so that at least one of your party can more easily swim you back in to shore when you want to go back. My husband was worn out by the time he got us back to shore because we floated way out to the ropes.)
The bahamas were good. We took a ferry ride to Atlantis for $3 one way but what the islanders don't tell you is that you're not being dropped off "right" at the Atlantis. You have to walk and "find" your way there. The Atlantis only lets you in a part of their hotel and you can not get into their outside stuff unless you have a day pass or something like that. We asked how to access the public beach and were given directions to go out front door, turn left at next street and go past comfort inn. The problem was there are no clear signs to tell you were to turn left to access the beach so we walked at least a mile down the road missing the spot. But when we finally got on the beach, it was gorgeous!
If we would've turned where we were suppose to we could have rented chairs, jet ski's, banana boat etc. right there. Although our own exploring was not exactly what I expected I would still suggest getting off ship and going in building and booking excursions directly with the islanders. Much cheaper. When we left the beach (from the road that we should've entered the beach), there were taxi's ready to take you back to the ship for $4 a person. Believe me we jumped on that!
The things that I didn't like about the gem were more or less incidental to us. First, the food was really good but the setup for the buffet was a little chaotic. Not so chaotic that it kept us away though, because we chose to eat there most of the time rather than the dining rooms. Secondly, the common area hallways were very narrow and felt more congested because of it. (It was hard for us to hold hands for more than a few seconds before having to break loose to adjust to the crowds of people.) The Carnival ship had very nice spacious corridors which were lovely. Next, we had a balcony room on both ships and the Gem's room was noticeably smaller. Also, I didn't like the way the stardust theater was set up. The chairs were just like movie theater chairs, tight and cramped. No leg room for anyone who has long legs plus the bar service people had to pass your drinks down the row along with your card and receipt for you to sign. The Carnival Liberty had nice lounge, couch-like seating with tables in front of you to put your drinks down AND bar service and anyone else had plenty of room to pass by you without you ever having to stand up to let someone by. Last but not least, I was not impressed with the drinks that I had. The Passionate Kiss was good (frozen, peach schnapps, passion fruit juice, etc) but the Rebellious Fish and the Strawberry Banana daiquiri I had on the private island were terrible. The daiquiri tasted like strawberry limeade without a hint of banana. (Although I did hear that the pina colada was good if you like coconut.)
So overall, it was an enjoyable cruise and I would cruise Norwegian Gem again.