We just finished a 12 day Grand Mediterranean cruise on the Norwegian Spirit. We've cruised seven times before, and this was just a fantastic experience. This comes from the viewpoint that I am not a cruise fanatic. I prefer to travel on my own, spend multiple days or weeks in one location, and figure out logistics by myself. So all-inclusive tours aren't my thing. But if they were, this would be the way to go.
The Norwegian Spirit was built around 1998 and refurbished in 2011. It is not a "mega-ship" in the 4000 passenger range, but a mid-range 2000 passenger ship. This is a personal preference, but I find the smaller ship has a more intimate feel to it, and on a Grand Mediterranean cruise, you're spending most of your time touring ports of call (or should be), rather than using ship's amenities. Refurbishment was excellent quality.
The ship layout is typical. We have sailed on Carnival, Royal Caribbean and Norwegian, and there is a fairly standard ship design. All have open atria which extend upwards from the main entrance (in this case deck 7) deck to the top deck and a two-deck "main atrium area" with a double grand staircase connecting the two decks. Buffet dining is on the pool deck, main dining rooms (2) are on deck 5 mid ship and aft. Two-deck theater aft and numerous lounges, restaurants and meeting rooms.
Decor is tasteful, mostly wood and polished metal surfaces. Not the over-the-top Vegas-style design of Carnival ships (not criticizing...it's a very well executed Vegas-style design). Maintenance is flawless. Everything clean and in good repair, but was just refurbished a year ago. Strong emphasis on board on hand-washing. Sanitizer stations at entrances to all public areas, and "washy-washy" people with spray sanitizers at entrances to buffet (outstanding idea) and the main dining rooms.
I am not a fan of formal dining or of dressing up at all, although I'll make an exception for weddings, funerals and customer meetings. Norwegian's "freestyle cruising" suits me just fine. There are no fixed seatings for the main dining rooms. It's just first-come-first-served. The Spirit has fewer price-included dining options than mega-ships have; just the buffet, the main dining rooms, a small 24/7 eatery on deck 7 and a sandwich bar on deck 12, but these were all good. The only thing you're missing out on is free pizza 24 hours a day, which a lot of ships offer.
There are quite a few fixed-price specialty restaurants on the Spirit. You pay a fixed cover charge, which varies by restaurant, and order whatever you want. I did not try any of these, so have no comment. The food in the main dining rooms and on the buffet was surprisingly varied for a cruise ship, in my experience. Particularly on the buffet, I'm accustomed to pretty much the same food showing up every day. While this is true for breakfast, the array of offerings is staggeringly large, and includes pretty much everything you would expect. I don't think you can piece together a traditional Japanese breakfast from it...but pretty much everything North American, South American and European is there somewhere.
Food quality is outstanding...fresh ingredients freshly prepared. Even the buffet has a station with a chef cooking fresh seafood specialties on demand. Just keep in mind this is a cruise ship and not a floating five-star restaurant. Set your expectations appropriately. For diabetics, there is always a decent assortment of sugar-free desserts, but they are largely based on sugar-free pudding and sugar-free pound cake. Not a lot of creativity here. But typical for a cruise ship. Will say that on the last day they produced a very respectable no-sugar-added apple strudel (apples contain sugar), so they've got it in them. I applaud the effort.
We had a balcony stateroom on deck 10, and it was more than adequate. Notable was the compartmentalized bathroom, with separate closable shower, sink/vanity and toilet areas. I've never seen that on a cruise ship before. Soap and shampoo are provided. Although this is now a standard on cruise ships, it didn't used to be, and probably arose from the ongoing problems with Norovirus and hygiene issues. Plenty of storage space and a small safe.
Friendliest staff I've encountered on a cruise ship. For the most part, they genuinely enjoyed their jobs and enjoyed working with one another. They were very open to discussing working life on a cruise ship, what they liked and didn't like and were clearly encouraged to just be themselves rather than corporate fabrications. Refreshing.
Again, in terms of entertainment, this is a cruise ship. We aren't on Broadway or the West End. Would make the cruise a lot more expensive if they had to bring in the "Book of Mormon" touring company. That said, the entertainment was quite good overall. They had a staged set-piece called "Elements" that was quite impressive for ensemble NCL-created entertainment. And the soloists they brought on board (a juggler/comedian, a magician, a violinist, an aerial acrobatics couple and a singer comedian) were mostly excellent (didn't care much for the singer...sorry). Did not engage much in ship activities because touring ports of call took most of our time.