FOS is fantastic -- very beautiful and I liked the large size. DH found it a bit crowded as there were lots of kids making it 4 in some rooms but we really didn't feel it. Spent a lot of time in the Diamond lounge for breakfast for me and drinks prior to dinner. The lounge is in the Viking Crown Area and has floor to ceiling windows.
The service was the best overall that we had a on a cruise -- everyone was fabulous and our waiter, Wan, and the Diamond Lounge concierge, Carmeliza, were even a cut above that.
There was a very interesting passenger mix with a large group of Brazilians, another group of Norwegians and many other folks from Europe and I think South America. As Brazil and other places in South America are opposite from us seasonally, I would expect that many of the kids were on summer break. The Brazilian families and many others had babies and small children. Lots of strollers.