Overall we had a great holiday on the NCL Spirit, and would travel with them again.
If you're planning a cruise (during winter) be aware that most of the sea days within the Med are cool until you get closer to Madeira and the Canary Islands.
Issues:-
The Shower/wash room wasn't as clean as we would have liked (or expected). There was quite a lot of staining in the grouting tiles and some tiles were broken. Generally as you look around the washroom you can tell it's not had a good clean in a long time. Also there was dust evident around where the TV sits which again indicated that it hadn't been cleaned in a while. I don't know if this is because the turnaround time is so quick. We wiped it down in the end.
The lining of the curtains also had quite a lot of marks/stains and the tie backs were broken so you could not use them. I think our general impression was a lack of maintenance.
Balcony is small just enough room for two chairs and a very small table. Table had some stains; we cleaned it in the end, but does the job at the end of the day of some outdoor space...
Our room attendant was good, but I would avoid this room again as he sets up his cleaning cart outside so there was often noise, and also it is adjacient/above the main entrance/exit at Barcellona where they play loud welcoming music.