My husband and I sailed on the Dawn as our 26th cruise. We have cruised the Mediterranean, Baltic, Caribbean, Alaska, and Asia on Carnival (1), Disney (1), Princess, Royal Caribbean, NCL (4), and Celebrity. We have also traveled widely throughout Europe and Japan, so you can judge that we are experienced cruisers and travelers in general.
Demographic: In terms of this cruise: me. 65, reasonably mobile, and chubby. There were a handful of children on board, some truly ancient people, quite a few elderly running along a continuum of disability, and a few dozen younger adults, but for the most part, the average person on this voyage was my age and shape. This, of course, influenced the dress and behavioral norms on the cruise. Yes, I did see the odd person with fuchsia hair or orange hair and the odd drunk, but for the most part dress and behavior was conservative.
Embarkation: It seemed to take forever, but it actually involved an hour's wait. We got there about 12:30 and were on board shortly after 1:30. NCL handled the volume of people well, with those who were waiting seated in rows of chairs and called by row. Of course, there were people who cheated, seating themselves in areas that they should not yet have been in or entirely skipped the rows of chairs and directly got in the last line for check-in, but most everyone was orderly and considerate.
I commented somewhat in the review. Do know that you can hear deck chairs being shoved around at 5 a.m. every morning. Also the walls are very thin. The room is in a great location, midships, exactly one deck below the buffet, exactly above the atrium (several decks).