We were curious about Eastern Europe, and Croisieurope's itinerary seemed the most interesting. Mostly older French-speaking passengers, with a sizable Spanish contingent. Only six English-speakers, but Omer the cruise director kept us informed and made sure there were English-speaking guides on the excursions. (Although my French is limited - 30 night school classes 25 years ago - I found myself understanding nearly everything by the end of the week). Excellent food and interesting excursions with good guides. A low-key and pleasant eight days.
Shore excursions were generally very good. Was somewhat disappointed that the Constanta tour didn't include the beach, and the "included" noon meal could have been skipped -- large restaurant catering to tour groups with mediocre food and slow service. We would have happily paid for our own meal at a beachfront restaurant. Also, the Bucharest tour seemed very rushed, possibly of necessity. There was no time to do justice to the outdoor folk museum.