I've been on two of the river cruises in Europe, and they are as you describe. My husband and I used to travel by renting cars, making our own arrangements, etc. But now that we're older, we don't want to haul our luggage from city to city and drive in strange cities, so cruises are perfect. We've also discovered they're not any more expensive than other ways of traveling. I can't take the bus tours, because you have to be out of the hotel, luggage packed, early in the morning as you go from place to place.