The Viking Ingvar is a 27 year old ship, built in East Germany, that has been cosmetically renewed but is still an old diesel-powered barge. Our cabin was in the aft part of the vessel on the third deck and we got very little sleep while the ship was under way because of vibrations and noise from the engines and operating equipment. What a bummer. I understand that there are others in INGVAR's class, so beware!
The food was also a disaster. Not only was most of it inedible but the portions were very small. The wait staff was mostly Filipino and were not interested in serving the tables.
Apparently Russian rules require that the River Cruises be kept outside the cities when they are docked. It was an expensive cab ride to get from the ship to the nearest subway station in St. Petersburg although a local Russian style bus was also available for much less cost. The ship is moored at a terminal in Moscow which is also some way outside of the city. The nearest subway station for that location is a 1/2 mile walk.
The tours were interesting but be aware that most of the more interesting ones cost extra. The additional costs were quoted in "units" which translated directly to euros because Viking is fiddling with the Russian currency rules. 1 unit = 1 Euro. Since the dollar is currently worth about .77 euros, the cost of a 44 unit (per person) tour comes out to be about $57 dollars each; watch out.
On balance, this was not a trip that we would have taken on Viking had we been aware of the above. Some of the problems can be traced to the fact that the location was Russia, and not central Europe, but for the cost that was paid,
the value was not there.