Overall, I'd rate the whole experience 4 out of 5. This was our first cruise, so I'm not sure I have much to compare to.
I really enjoyed the 'freestyle' aspect - I find it more relaxing. Things stayed pretty cazsh. I don't like when they ask you to dress formally - i.e girls have to wear dresses, and men have to wear suits. There were a few restaurants that required less-casual attire (no flip flops, and no shorts), which was perfectly fine.
The shore excursions were okay. The actual excursion was fantastic, but getting to the excursion and back on each of the islands was a bit of a debacle - mainly because of the way the excursion companies are (un)organized. I don't think NCL can do much about it and don't hold this against them.
Shopping on the ship was pure crap, and I suggest you plan not to shop. I was mainly irritated with the 'special' sales. Let me tell you that these sales are anything but special. For example, they had a watch 'sale', where they were selling watches for $19.99, that were regularly priced at $80 to $100. The sale would only last an hour. They made such a big deal about the sale, that everyone showed up, and it was just plain chaos. The watches were NOT $100 watches - that was a lie. As was the whole one hour aspect - I happened to walk by the store the next day and saw the same watches still on sale for $19.99. So my word of advice - don't fall for any of the 'specials' on the ship.
Entertainment - perfect. Nothing more to add :). I don't know how it compares to other ships.
Dining - perfect, lots of options. Not sure how it compares to other ships.