We just returned from a Christmas tour on Norwegian. For comparison purposes, I have previously cruised with Carnival and Royal Caribbean. While I will lay out the positives and negatives below, the overall experience was disappointing and I will never recommend Norwegian nor travel on Norwegian in the future.
Positives:
-Embarkation process went smoothly with line to check in moving quickly
The cabin was laid out to be comfortable and maximize storage capacity. It was also very clean. We really enjoyed having separate spaces for the toilet, sink and shower as it allowed us to get ready at the same time without having to deal with a shared bathroom. Once person could be in the separate shower while another person was using the toilet. The balcony was also roomy.
The island was not very nice. It had man-made sand and murky water. Also, there were way too many people in a very small space. We returned to the boat after 2 hours.
We took a private Bob Marley tour which was pretty fun. In general, Falmouth doesn't have pretty beaches or an interesting downtown. I think Ocho Rios might offer a better port for Norwegian's itinerary.
We went to a private beach club which was fine. Not much to see or do downtown or near the port.