I just returned from a week long cruise on the Nieuw Amsterdam. The rooms were rather small compared to what I have experienced on other cruise ships, such as the Konigsdam. The one big issue was that one entire wall had NO electrical outlets by the beds. My roommate has a CPAP machine and there was nowhere to plug it in by the beds. The steward had to bring us an extension cord which was about 20 ft. long and was thick enough to power a farm. This was not very convenient and was a tripping hazard. Apart from the bathroom, the living area had only the one outlet at the desk. This seems like a very major over sight.
There was a sauna to use free of charge, but it was very small and not in the spa area. It held maybe 4 people comfortably and I often had to wait for people to leave before there would be enough room. There was not enough clothing hooks and there was only one shower. There are separate men's and women's sauna right off the main hallway on the Lido deck.
The HAL website advertised a .750 liter bottle of Bacardi for $43 to be delivered to one's room the day of departure. They also advertised the same bottle with 3 cans of coke for $56. I bought the $43 bottle ahead of time on the website. However, when I got onboard, they were advertising the same bottle with 3 cans of coke for $43. I cancelled my original order and placed the order for the bottle and 3 cans of coke. When I got the bill, they had added a 15% gratuity fee and tax, which brought the price to just under $50. The original charge was just the $43, so I recommend buying BEFORE you get onboard.
Very nice beach, but the lunch served had a very limited time. It was not an "open" buffet to fit your own schedule.