Our first river cruise. The hotel in Paris (Le Meridien) was nothing special, small room looked a bit worn but Prague Hilton was nice. It was hot in Paris/Germany/Prague during our trip. The A/C in the ship's dining room had some trouble keeping it cool during dinners but our cabin (Veranda Suite) was always cool. Most of the tour guides were excellent. Entertainment on-board was just okay. Enjoyed the sun deck when it was open (part of the trip has low bridges mandating closure of the sun deck).
If we we do another river cruise, we will do one where all nights are on the ship. The long bus rides Paris--->boat--->Prague and all the baggage handing were a hassle. But all-in-all it was a good, fun experience. Met some great people.
Nice but pricey. The shower leaked onto the bedroom carpet a bit but that was the only issue.