I highly recommend traveling on the Navigator of the Seas. Our cruise was to the Western Caribbean over Christmas, and Royal Caribbean did everything possible to make this as pleasant an experience as possible. One word of warning: avoid connecting flights on Delta Airlines through Atlanta, if possible. Delta lost our luggage and this dampened our experience to some extent. Very high marks to Royal Caribbean for doing everything in their power to assist us and to provide clothes, toiletries, etc. to compensate for the lost luggage. Royal Caribbean staff acknowledged that they have had more difficulty with Delta than any other air carrier. If you are traveling from another city, we highly recommend coming in the night before and staying at a local hotel. The peace of mind, alone, is worth the cost of the hotel room. Shipboard accommodations on the Navigator are comfortable, clean, and convenient. The limited space in the cabin is offset to some extent by numerous cubbyholes for storing your personal items. The cuisine in the main dining rooms is not spectacular; but it is consistently very good and there is plenty of it. The service in the main dining room is impeccable. My 16-year old son particularly enjoyed the Living Room (a teen lounge), where he found ready companions who were much cooler than Mom and Dad. Although the pool area is lots of fun for younger couples (a variety of high energy bands playing different types of live music), our favorite spot was the Solarium, which had all the advantages of the pool area, but without the loud music and more shelter from the wind. There is a great variety of live music for every conceivable taste in the numerous shipboard lounges.
With respect to shore excursions in ports of call, Royal Caribbean has done its homework and has affiliated with reputable and fun tour operators. Labadee, Haiti was particularly fun, since you are not competing with other cruise ship lines.
With 3,000 plus passengers on board, there are always bound to be a few people who behave badly. Royal Caribbean staff handled such matters quickly, quietly and discreetly, with a minimum of disruption.