We just returned from a great trip on the Dawn to Bermuda from Boston. The cabin and food crews were very gracious throughout, the food was quite good overall (especially the NewYork strip steak at Cagney's), the entertainment by the Production Cast was superb (we especially were awed by the performance of the husband/wife acrobatic dancers in "Ocean's Apart"), the other entertainers throughout the ship were also good, and the entire on-board experience was very good. We did miss an adults only pool or hot tub area as in the afternoons especially the one pool and the four hot tubs around it were very full. In the mornings and evening though I often had the pool to myself and could do laps.
In Bermuda, we went twice to Snorkel Park (where admission ranges from $10 to nothing depending on when you go!) which is a small beach but quite good for snorkeling as there are a lot of fish around the reefs and the old fort foundation. I also took the excursion on a catamaran for snorkeling which also was good but I didn't see anything different there in terms of species than I saw in Snorkel Park. It was nice to sail around though to a different part of the island. We also went to Horseshoe Beach which is very different from Snprkel Park in that it is open ocean so has a lot of wave action.
I'd certainly consider Norwegian for another cruise.