In general, European river cruise ships carry between 150 and 190 passengers. Guided bus tours tend to include far fewer travelers, with only 40 or 50 people and some luxury tour operators, including Tauck, offer land tours that max out at around 25 passengers. Smaller groups mean less anonymity and a lot more time bonding with your traveling companions — which can be good or bad, depending on your personality.

On a river cruise, a daily excursion (typically in the morning) is included in your fare, with passengers separated into four or five groups of 30 or so people. These city tours, bike rides, and vineyard or castle tours are conducted by local guides and usually last about four hours, timed to get you back to the ship for lunch and sometimes an afternoon of sailing. If you are staying longer in that port, you might be offered additional afternoon or evening excursions (usually for a fee), which could be a music performance, dinner, or a brewery visit. 

Land tours feature long days — usually departing the hotel after breakfast and ending late in the evening after group dinners or organized entertainment. Most tours do give you free time in the middle of the day. These breaks mean lunch on your own and the opportunity to sample the local cuisine, though it's worth nothing that these meals are not included in the tour price. Want even more time on your own? Since lodging is most likely close to the main attractions, you also have the flexibility to choose to spend a day exploring on your own and skip the main tour altogether.

The simplicity of having the same cabin is the key appeal of a river cruise. Unpack once and you’re set for your voyage, whether you’re sailing down the Rhine River in Europe or cruising up the mighty Mississippi. On average, standard river cruise cabins are a cozy 150 to 170 square feet and top-level suites max out around 300 square feet. 

On a land tour, you have to pack and unpack frequently, staying in up to six hotels for a 10- or 11-day trip, for example. This can be a grind, but you also get a chance to see a variety of properties — and try buffet breakfasts, many of which offer local specialties, from a lot of different chefs.

Cruises have you sailing along occasionally very scenic stretches, where you'll pass sights such as the medieval castles and fortresses on the banks of the Middle Rhine. And while the ship is on the move, you can spend the time sitting on the sundeck, reading in the lounge, or napping in your cabin.

Land-based trips can have you on a coach from early morning till after dark with their packed schedules, though sometimes the view from the bus window — of, say, vineyards or charming little towns — is just as appealing as from the river. There is some flexibility with the transportation, and you might even find yourself on a boat when the destination calls for it (Globus, for example, gives guests a grand arrival in Venice on a private boat). Other times, you may travel on highways, confined to your bus seat.

On a cruise ship, you get to build a rapport with the same crew members for the entire trip compared with the ever-changing cast of waitstaff you have for meals and in hotels on a land tour. Each day on a river cruise also has a specific flow that you can count on: breakfast, morning tour, back to the boat for lunch, afternoon sailing or optional tour, dinner, and entertainment — such as a performance by a local dance troupe or pianist playing standards in the lounge.

Land tours often give you more chances to interact with locals, including bartenders and waiters who live and work in the destinations you are visiting. The itinerary is also less regimented, with more free time. If you are a night owl, being at a hotel near the city center makes it easier to explore a city’s bar or music scene on your own at night.