We took the AmaSonata Danube cruise from Budapest to Vilshofen over Easter 2019. We did not do the pre-cruise add on, but did arrive in Budapest a few days early, staying at the Hilton Budapest by the castle. This was our first river cruise, and it was generally a great experience (helped by beautiful weather). The embarkation was incredibly smooth. Our taxi dropped us off about 30 minutes after the first cabin access, which worked well because no one else was boarding. Crew members took our luggage and that of our companions. Check in was minimal - mainly picking up the key and getting our picture taken for security. We were whisked to our cabin where our luggage was already waiting. The woman who showed us our cabin (one of the servers in the restaurant we later learned) identified a loose handle and had that taken care of quickly.
Dining: buffet at breakfast, though you can order additional items. Buffet at lunch, always with a carving station, but the servers take orders for optional soup and entrees. The soups were always very hot. Sometimes great, sometimes so-so. Dinner was starter-soup-entree-dessert. The food was good but usually not outstanding. The servers were great, though. We were trying to be healthy at least sometimes, foiled often by being given a second dessert or alternate treat. Only one selection of white or red wine at dinner, but they changed each day and were usually local to the country. Lunch and/or dinner each day often offered local specialties. There is a second small restaurant that you have to make reservations for. A menu is posted outside - note that they have the same menu every day during the cruise. We failed to make reservations early so could only get a night that would have been a later dinner. We later canceled the reservation deciding that we preferred the main restaurant. Note also that tables in the main restaurant seat 4 or 6 people. It is open seating, but we found relatively little mixing from night to night (we were a group of 4).
Shore excursions: the shore excursions were generally good. At each stop, there was generally a walking tour, a hike and a bike tour. The walking tours always had a gentle walker and regular walkers option. I had read that there were also active walkers options, but that was only true in Vienna. We were a bit frustrated with the Budapest tour because we had already seen several of the places on the tour -- we couldn't figure out in enough detail ahead of time to know how much to avoid going to early. We had a long free time in the market hall (which we had been to) and then very little time in Heroes Square, which we hadn't been to because it was farther out. (The basic tour was a mix of bus and walking). Other than that, the tours were good. They were always led by local guides, and groups tended to be fairly small (12-15 people, more if there was a bus). The buses were very comfortable and never full (perhaps because the boat wasn't at capacity). I also wish I had known earlier that "hike" wasn't what Americans would call a hike. Hikes generally meant up hill (usually to a castle) and often on cobblestones. But these were not difficult or nature walks. We did the hike in Bratislava and found it to be one of our favorites as it was more like a more robust walking tour. Bike trips, on the other hand, tended to be long and pretty strenuous. We worried that things would be closed over Easter, but all the tourist sites were available, including museums that would have been closed on our Monday in Vienna, but were open for Easter Monday. Most of the cities also had Easter markets.
The cabin was nice and the bathroom was not as tight as I feared it would be (and the shower was great). The AmaWaterways ships are unusual in the share of cabins with balconies that you can sit on. This was great on the days that we were cruising and nice in the morning or evening. But note that the balcony is carved out of the room (that is, the boats all have flat profiles). Also, there are many other river ships, and in many ports, they dock together (so passengers from one ship have to pass through or over the other to get to shore). This means you may not be able to use the balcony when the ship is in port, because you have the windows of the other boat's cabin right up against yours. It doesn't matter which side of the boat you are on, because sometimes your boat is on the inside and sometimes it is on the outside. With lots of other ships in ports (especially in Vienna), we did compare the ships. One feature I liked on the AmaSonata was that the public rooms (the lounge and restaurant) were offset 1/2 deck from the guest cabins - this isn't obvious in the deck plan, but makes the cabins seem a bit more private. It does mean that there are always a few steps up or down no matter where you are going. There is an elevator but I never saw anyone use it.
We did the Castle "hike" which was really the city walking tour plus the castle. It went up hill but was otherwise not strenuous. We really liked Bratislava.