We chose UniWorld as it had been recommended to us by a friend and were interested in river cruising. We had only been ocean cruising before and were interested in the smaller, all inclusive value of a river cruise. We were not disappointed at all.
Boat: It's nice, clean. We enjoyed the common area, the dining room and the sun deck up above. I will say that when everyone gets in the dining area or bar, it can get very noisy because of the low ceilings, but it wasn't really a problem or us. We had lovely weather and quite enjoyed the sun deck.
Room: It was small - very small, but once again not problem. We did expect a small room and were already informed about the lack of a balcony. There is a floor to ceiling window that can be opened. There are often other boats docking with you, so the view can be into another boat, but probably more than half the time, we had a wonderful view of the Danube and it's beautiful scenery.
Small , but clean and adequate. Coming from the US, we asked for a top sheet on our bed instead of just the comforter as the comforter was just too hot for us. It was no problem and our attendant made up our bed with a top sheet each day. Bathroom is small.
Bus ride from Prague to Nuremberg was long with one stop at McDonalds. BUT our guide in Nuremberg was fun and cute and very, very knowledgeable. We enjoyed the City Market and the Castle Tour.
Enjoyed the small village fill of Regensburg. Had a fun day with a couple of tours, then a little free time. Prefer the small villages to the big cities.
Tour was fine, but there wasn't anything of interest to see in Vienna.