We've cruised every major line out there at least once including Carnival, Norwegian,
RCCL, Princess, Celebrity, and Disney and there is ALWAYS something that doesn't go right no matter what line we are on.
We had issues on our May
DCL cruise just as you sited on the Norwegian line. We had sewer issues in our room that took 2 days to get completely fixed and we gagged everytime we stepped foot into our room. We had blistering hot water in the showers and sinks while in port one day so we couldn't take a shower or a bath. I could go on and on....my point is that every single ship has SOME kind of issue on it.
Norwegian lost our luggage and it took us forever to get reimbursed, on RCCL we were assigned a room that was already being used by another family, on Carnival a man died and we left the port 6 hours later and missed the next port, Princess left us standing at the airport waiting for a bus that never came and by the time Princess admitted it had made a mistake we had to get a taxi and barely made it on before the lifeboat drill and then they refused to credit us or give us any kind of reimbursement, on Celebrity the swimming pool broke down 2 days and 2 other days someone pooped in it and they shut it down for the remainder of the cruise. As you can see bad stuff happens on EVERY single line and can happen at any given time.
I don't think anyone can make a solid decision either positive or negative about a line based on someone else's subjective review. Two people experience the same cruise differently so while one person may have had a terrible experience on the cruise others gave it a glorious review!
Only you can decide if the gamble is worth it to try the line yourself but generally the only way to know how another line is for you is to try it out.
Heidi