Wanted to see the Hanseatic cities so this fitted the bill.
Positives:- Good itinerary, but we did our own thing in ports, usually using the excellent public transport. I'm fluent in German, which helps.
Food very good. Cabin nice. I can't comment on the entertainment, as we didn't bother with any of it; it's just not our thing. Nice to have Bridge lessons on sea days. Plenty of activities; unlike many cruise lines these did not just involve trying to get you to spend more money on rubbish. (Usually.) Plenty of space to sit and read quietly, even though, being April, it was too cold much of the time to sit outside when under way. Drink Prices very reasonable, unlike a certain large USA-based group. Ship fully refitted a few years ago, but it looked all very new. Carpets just fitted I think.
As above: spacious, reasonable size of window but NOISE from above.
Kiel itself was largely destroyed in the war so there is no "old town" really. We took the train to Flensburg and that really WAS worth seeing.