I have cruised with Carnival, Royal Caribbean and recently with Norwegian.
I went on Norwegian because I was interested in the Free Style cruising. I loved the idea of eating with who I wanted when I wanted to eat and wearing what I wanted to wear. After all I feel if I'm on vacation I should be able to do what felt good to me. I've never liked having to sit with strangers, or having to get dressed up on my vacation. I was very impressed with the food on Norwegian. It was also wonderful to go to dinner dressed comfortably. However, the ship did not compare to Royal Caribbean. It was kind of closed in, it wasn't open like Royal Caribbean ships. I felt a lot of that was because of all the different places to eat. This was a great feature but I think there could have been a better design when building the ship so that it didn't feel so partitioned off.
The entertainment was not at all on the same level as Royal Caribbean. Since this was only a two night cruise I'm not sure if this was an accurate representation of what the entertainment would be on A 7 or 9 night cruise but I don't know if I want to take the chance to see.
I realize that cabins are not large but the toilet area of the cabin of Norwegian was so small you could barely get up from the toilet. If I were overweight I think you could get stuck in there.