We did Budapest to the Black Sea on Viking(through Slovakia,Serbia,Romania, Bulgaria,Croatia) and back to Venice (14 days) a few years ago. We thought it was a great trip--the tours in these Eastern European countries were really interesting, the boat was nice and the food was great. We'd definitely do another river cruise with a Ngaire group, but we'd want to do more than just seven days. I wouldn't be too interested if the cruise line was European and we had to pay in Euros--unless the exchange rate improves significantly.