We embarked near Prague (Melnik) and exited in Dessau (near Berlin). The trip was a very good one and uneventful.
The stops were good except for the Meissen China Factory tour. Perhaps Viking gets compensation for this in some form as it is really a waste, except for the town tour. A highlight was the optional Terezin POW camp tour. Be sure and take it.
The boat is small, the room was smaller (class B" cabin), the food was average (which is good for those of us who don't want to gain weight on a trip), the premium beverage package is a waste of $$ unless you plan on staying on board and drinking all day, (you can bring your own liquor,etc. on board, wine is served with dinner) the Viking employees are excellent, tours and guides are excellent, overall, a good trip but a bit overpriced.
These tours are not for the feeble or those unable to enter and exit tour buses, walk for one-half day, etc. So if you envision a "cruise", this is more of a floating hotel with stops and tours every day. I would advocate taking an extra day or two in both cities (Prague and Berlin). We used Viking for the air and they get discounted seats so don't expect any better seating than "tourist" unless you upgrade. Be sure and AVOID Charles De Gaulle Airport in Paris if at all possible. We just transferred there and it was awful. It is beyond a dreadful nightmare. And for trans-Atlantic, I'd recommend an American carrier as well. (Air France is no fun to fly.)But Zanex is actually a great drug for air travel.