Having read the reviews, I went with low expectations for the ship. I was pleasantly surprised in many ways. First, the staff onboard were friendly and anxious to please and be helpful. The AMA guides were very, very good at their jobs - most knowledgeable and ready to answer questions as well as being masters at keeping up with tourists who tend to wander from the group. We were herded through the most crowded and challenging circumstances (for them) with much skill. No one ever got separated unless they chose to go off on their own.
The dining rooms on board - and there are two, surprised me with the variety of food available at all meals. Some of the dishes cooked were better than others, but never did I feel underfed. I could have lived off the wonderful soups, the various salads offered and the fresh bread. Luckily I didn't have to do that, as there were many other dishes to choose from. Waiters and waitresses were young - many college students at summer jobs - and made up for their occasional lack of serving skills with many smiles, much attention to diners' needs and a great desire to please.
I heard some passengers, who had cruised with AMA to other European ports and were disappointed with the style and luxury level of the ship, say that the cabins were like a Motel 6. I really can't argue with that, but the cabins were cleaned daily, the beds were comfortable and the water pressure in the showers was fantastic. Frankly, that suited the two of us. Luxury is nice, but in order to see a good bit of Russia and not have to pack and unpack, I found the cabin to be a good trade-off. All the cruise ships are Russian owned - the cruise companies can refurbish the interiors.
There was no feeling of discomfort for us due to the political situation in the Ukraine. There had been a fair amount of cancellations on the ship, but everywhere we went was packed with tourists from all over the world. The tourist industry in Russia may be suffering this year, but it was surprising to me how many tourists were there (we all go to the same ports) on the river cruising and in the cities. We never felt unsafe in any way, except from being trampled by tourists in the Hermitage.
We had a wonderful time. AMA Katerina is a good choice for this trip.