We did a Backroads "epic" trip to the Tour de France several years ago. It was great - the riding was really good and the guides were awesome. We rode by some Butterfield & Robinson buses - my impression was that B&R was a bit more about the luxury and less about the riding than Backroads. Although the easier level Backroads trips are likely less about the riding. I think Backroads has trips to suit just about every riding need (lots of miles or not as many).

I loved the rides they planned for us - I did wish we had a bit more time no our own to just poke around and explore on our own. But that was probably a function of the fact our trip was "epic" and they had to fit in some super long rides along with Tour viewing. It didn't leave much time for poking around on your own.