River cruising to historic venues is different than ocean cruising. The emphasis is on the places you visit, not the entertainment/fun/gambling etc, on-board ship. River cruising is not for everyone. There are no swimming pools or casinos or discos or men's hairy chest contents. Viking does a wonderful job with providing knowledgeable guides and excursions that give the information and cultural experience that these cruises are all about. The populations on these cruises is generally healthy mid-to-older English speakers, with an occasional young person, but no young children. Viking cautions that disabilities may prevent you from engaging in most of the excursions, however the ships have elevators.
The food is excellent, as is the service. One night we had fresh fish from the Lake that we were presently transiting. Another day, breakfast cheese from the local market was served. Food was Russian themed and prepared expertly by our Austrian chef. Meals are one sitting with no assigned seating allowing the opportunity to meet many different people. The small size of these ships keeps the atmosphere fairly intimate compared with large ocean liners. The accommodations are the best on the rivers, not glitzy, but attractive and providing all amenities. Entertainment is low key, with some of it provided by evening excursions to shows: ballet, folkloric, etc. and on-board demonstrations and associated fun: vodka tasting, Moscow at night city tour. There are also historic info talks by knowledgeable staff. The "shopping talks" that are standard on cruise ships here are truly informational and not specific to stores or pushing vendors.
We have travelled with Viking twice and would not hesitate to use them again. However, personally, we would not take a river cruise within Europe(other than Russia)as we would prefer to travel on our own by car or train and staying in hotels in order to more experience the environment. In areas of the world where the language and depth of information require a tour, river cruises are a wonderful solution. We were able to see more of Russia than we would have been able to experience any other way and in a more comfortable/affable environment than an other type of tour/cruise would allow.
Baltic cruises only allow you to see St. Petersburg on a limited basis. We saw many other historic towns and Moscow as well as did a home visit with a Russian family in Uglich. We also went to Kizhi Island (a UNESCO world heritage site) which is fairly inaccessible except by boat and saw churches and buildings built entirely of birch and without nails. This cruise was well worth the trip (and hassle to get a Russian visa). We have gone to China with Viking and if Egypt becomes safe again we will go there.