I should start out by saying that this was my first NCL cruise. I have cruised three times prior on Carnival and loved it. My parents took this same cruise and they loved it.
My husband and I took this cruise for our honeymoon, as we wanted to see as much of Hawaii as possible. And this cruise is a great means to that end. You get to see 4 islands and have plenty of time at most of them to do whatever you want, especially since you are in port for two consecutive days at Maui and Kauai. One note about the ports, they are all industrial ports (with one exception). There isn't much in walking distance from the ports, so you will largely have to rely on free shuttles, taxis or a rental car. The only port that isn't industrial is Kona, which doesn't really have a port due to the protected reef. We actually had to tender (i.e. take a smaller boat to the dock from the cruise ship) to get ashore.
As others have said, the staff on this ship is not of the caliber you've experienced on other ships I suspect. Most of the staff are American. The first two staff we talked to (both bartenders) complained to us about their job and working the bar. Additionally, throughout the cruise I heard staff complain, be reprimanded and generally not care. This isn't true for all staff, but I certainly never noticed any of this poor morale or behavior on Carnival.
We had a large balcony state room on deck 9, forward, starboard. I believe it was 9002. It was quite quiet, we never heard any other guests. The only downside to this stateroom was that the balcony was mostly enclosed and we never got any direct sunlight on the balcony. So while it was nice to sit out there and relax, it didn't provide a private place to sun ourselves. Not all the balconies are like this, just a few at the very forward of the ship.