We really liked the attention to details. Viking seem to anticipate potential glitches and addresses them before you realized them. Even when the ship was delayed in a lock, the shore excursion that was meeting up with the ship down river found that we were delayed and the Program director, not to panic, took the shore group to a pub to wait our arrival -- when the world gives you lemons . . .
It was wonderful to experience new places, foods, cultures both on board and on shore excursions. We added a few optional excursions that were of special interest to us however, the included ones were more than exceptional.
I would recommend bringing clothes with expandable waistbands as the food is top notch, it was plentiful. If anyone goes hungry, it is their own choice! The food service staff paid attention to every detail -- even noticed that my soft boiled eggs weren't soft and immediately reordered them.
While some had made comments before we arrived as to the room size, I found it so efficient that it was beyond expectations. Consider it "IKEAish" in feel and detailed. Can't think of anything I would change.