Navigator of the Seas is an amazing ship. Of course, this being my first cruise (my wife's third), I don't have a lot to compare it to. My wife had already sailed on Royal Caribbean twice before and when the idea came up for a cruise vacation, she refused to sail with any other line (and I can see why).
Cabin: We purchased an interior stateroom on deck nine (9369). The room is slightly wider than a king-size bed and long enough to fit the bed, a love seat, vanity mirror and table opposite the love seat, and a closet opposite the bathroom. Since it's an interior stateroom w/o a view, the room is pitch-black day or night when the lights are off, which is perfect for afternoon naps or a good sleep.
Embarkation: This was undoubtedly the worst part of our cruise. Initially, the boarding process was slow but steady...until it was our turn to be processed. With approximately 100 people behind us waiting in line, we were forced to wait behind a family of 5 from Norway. For some reason, it took FOREVER for RCCL to get these people on board the ship. We were not allowed to change lines and, as a result, all 100+ people behind us boarded the ship before we did. In fact, by the time we boarded the ship, there was virtually nobody in line behind us at all. I understand that foreign passengers with passports will take longer to board, but RCCL could have at least allowed us to move to another attendant to be processed. We waited in line for 30-40 minutes. Then we waited an additional 40-45 minutes behind the family from Norway.