We had done Viking previously and found them to be exceptional with cruise, sites, room, cleanliness, friendliness, food, service to and from airport, hotel accommodations in departure cities for extensions, and concierge service in extensions. Already booked next trip for next year. This will be my fifth cruise. Everything done with Viking seems to go smoothly. They are great with handicapped people and we even had children on one tour that was great. The extensions include a city tour and a number of other specialty tours are available through the concierge. Their optionals are well planned and reasonably priced. I like that each tour is different even though some towns ( on Rhine, for example )are duplicated, the sites seen and the spiel is different enough that you don't feel you are replaying a video. I will repeat some of these cruises because once is not enough. The food is great and the selection is varied, but you can always get something you like. They were very accommodating for vegetarians and gluten free diets.