We have booked a half-dozen walking, hiking and biking tours in Europe during the past three years. They are expensive to very expensive, by my lights, but don't assume that the more you spend the better your experience will be.
When we returned home I contacted an excellent, personable European guide we have traveled with before. Without telling him why, I asked him to quote the same Provence week, with the same hotels, meal plan and bicycle equipment.
For less than half what we paid our tour company for a self-guided trip, Gregory Grandet (firstname.lastname@example.org) would have booked and guided the whole trip personally, transported bikes and luggage (and us if we tired), and improvised with us if weather or other interests arose.
Ask whether the company you are considering has a representative on the scene whom you can call if troubles or confusion arise. Ask for references — these companies are not reviewed on TripAdvisor.com yet (though plenty of forum questions about them are routinely posted).
Get sample instruction sets and maps, see whether they include interesting cultural and historical details and recommendations for where to eat. If the instructions don't include mileages or the maps are difficult to make out, then look elsewhere.
In the mountains, hiking trails are well laid out in books such as Shorter Walks in the Dolomites, and on free tourist maps available anywhere. We could have booked the hotels ourselves and easily arranged for cabs to transport our luggage to the next stay without too much additional effort and far more cheaply.
On one recent high-dollar self-guided week, my hiking maps and instructions ranged from the indistinct to the asinine at times. Others using the same company told us they also contended with baffling and frustrating directions, despite the promising look of the website and promotional materials.
Many river cruises up and down the Southern France section of the Rhône are on offer. We have used Uniworld for a river cruise in the past, but we chose Viking this time, partly because of the strides it has taken toward eco-friendly boat design and operation.
We enjoyed both trips and would use these companies again. But check to see how often you are more or less confined to group tours, and how much free time you have for making your own plans at stops along the rivers. Ask, too, whether the onboard meals are with a group or if you have more private options. If you can splurge on a balcony room, do it.