Our cruise was a mix of some very very good experiences and some very very bad ones. First the good, the ships staff and the various Viking people we interacted with were all wonderful. The food was excellent and our cabin was first rate (and well cared for). The tours were also excellent and the guides were knowledgable. We liked the fact that we could participate in a tour or simply choose not to. The river views are magnificent and walking around the cities in the afternoon at our own pace was very nice.
Now the very very bad. Although not Vikings fault, we could not board at the advertised embarkation, instead we needed to taxi for over an hour to the next port to the north because of high water conditions. That extra time on top of the full day of flying was difficult. We arrived just in time for dinner, however we missed the first day's orientations. On the third day both my wife and I along with dozens of other passengers became very sick with some kind of illness. This lasted three days and we as well as many other guests could not leave our cabins. The staff was very attentive to our situation and provided round the clock room service. Dispite these issues we enjoyed this trip and have already booked a second trip with Viking.
The cabin was first rate. The Viking Sun is an older ship but the beds were comfortable and the room was well appointed. The Cabin Steward was phenomenal!