This is my 6th cruise on Norwegian. I love the free style concept, not being much of a party person or one who likes to dress up. The ship was very nice-- I was not put off by the decor as others have commented. The inside stateroom was VERY dark-- we expected this but I admit that it would have been nice to have a window even though we didn't spend much time in the room. The food was fine-- I suggest going to the dining room vs the buffet for breakfast if you don't like crowds. The hogging of beach chairs was a bit annoying, but we always managed to find somewhere to sit/recline.The staff was outstanding and fun to talk to-- some very hard working folks. I was very pleased with the lack of hard sell on the boat-- my last cruise, which was to Alaska a few years ago, was peppered with exhortations to attend this or that gem sale or Bingo. This was much toned down on this cruise.
Although I did a fair amount of research prior to the trip, here is what I wish I had known:
Venice-- I was overly concerned about transportation,choosing to stay near the airport, worrying I would have a hard time getting to the Pier. Transportation is easy-- bus, vaporetto or train all easy and inexpensive. Don't worry too much about getting around, it is a lot easier than many cities I have visited. If you can afford it, staying in Venice might be worth it; I kind of regretted we didn't. The airport itself is a mob scene- even at 6 AM!! Getting from the boat to the airport-- you can do it on your own.
Dubrovnik- the tender was a problem-- not going in but coming back, and we had to wait too long. I got the feeling there was a problem and this might not be a usual situation. Remember that if you go on an excursion through Norwegian you get first dibs on the tenders-- this might be worth the expense. We just took the bus (provided by NCL at no charge) and went into the city and walked around-- easy to do. We went to the Monastery and the War photography museum and just absorbed the lovely city and waterfront. There was a charge for climbing the wall so we skipped it. I think you could get a good sense of this stop without paying for an excursion.
Athens-- we booked the on off bus ahead of time through Priceline for about 1/4 of what the ship wanted to charge. You catch the bus right outside the terminal-- easy to find and seemed to run frequently enough. I would definitely do this on your own and not pay the rip off price for the excursions... we went to Parthenon, Agora, bazaar-- no problem apart from the heat, which an excursion wouldn't have altered!
Izmir-- there is an on off bus near the terminal here too, but it was already booked when we went off the boat, so if you want to try it, get off the boat right away (8 AM). I think the price was 10 Euro. Instead, we succumbed to one of the many entreaties from the cab drivers also right there. The driver spoke little English but somehow we managed to communicate and it was actually a nice experience (although it felt awkward at times to have him escorting us through the bazaar). Again, no need for an expensive excursion and the mosque he took us to was one of the highlights of the trip.
Split-- here we did spring for an excursion since we didn't want a repeat of the earlier tender experience. The tour of Trogir was excellent-- the trip to the beach resort was not really worth it. It wasn't as nice a resort as nearly any you can find in the US and the "pebbles" were so bad that I had to buy beach shoes to even go in the cold water. I am not sure what we could have done if we hadn't done the excursion-- I didn't see any obvious options as we got off the boat and the area we got off in was pretty commercial.
Good luck and enjoy your trip. I am happy to say we felt welcome everywhere we went, saw wonderful sights, ate great food, and made some great memories.