Service is king when you are on a cruise...and Viking appears to be the last place in the world that you can actually find it.
Housekeeping services multiple times per day--and automatically, not by special request.
I have severe celiac disease, or what most would call a gluten allergy. This is one of those things that typically makes traveling a nightmare. Not with Viking. Every morning the Matre 'd would provide the menus for all 3 meals, let me know what could and could not be prepared gluten-free, and I would order each of my meals for the day. At lunch/dinner, I would simply notify the wait staff that I had preordered, give them my room number, and they would bring me my pre-ordered meal. I would estimate that at least 85% of the items on the menu on any given day were able to be ordered gluten-free. As anyone with celiac will tell you, that is a cornucopia of options that simply does not exist for us in most situations. The fact that the foot was also universally excellent made it all the more remarkable. Did I mention that they even had gluten-free beer, not just available, but stocked in my room?
Spotless, bright, and comfortable. Bathroom was larger than some cabins on other cruises I have been on.
Impressively untouristed/commercialized for a capital city. Very walkable.
Don't miss the central city market. Beautifully constructed building given it's mundane purpose, and it is full of interesting/wonderful things.
We stumbled upon what can only be described as a magical Christmas village in a Biergarten just tucked away in a courtyard in the old town center. The rest of the town was charming, but it could have fallen off into the river and the Christmas village would still have been worth the stop.
Not my favorite port. A little too urban/industrial for my taste, but that's a matter of personal preference. I have no true complaints though. I have been told that the local art museums are great, but due to the short time in port, that was not really an option for this trip.
Picture perfect Christmas Market. Simon of Passau (a confectionary company) gave a presentation on the history of gingerbread that was spectacular (and so, by the way, is their gingerbread).
I have been to Vienna before, not as part of a cruise, and was there for a full week. The standard port-of-call excursions and a 1-day stay really do not do it justice. If you are limited to one day, I would skip any standard excursions and just go directly to the winter palace in the morning and start with the Schalzkammer exhibit. If you make it anywhere else that day, then great, but don't count on it. If you have time, I would swing by the summer palace, especially if the weather is nice, as the grounds are just as spectacular as the palace itself.