I did this ride the summer of 2000. After being overseas for 11 years I wanted to reacquaint myself with the U.S. It was pretty good. It's not an organized ride in the sense you ride as a group. However, we started out that way from Chicago and did that for about the first day or day and a half.
After that people seemed break into smaller groups and do there own thing. I think you could have stayed in any town at any motel you wanted but we sort of all ended up staying at the same hotel each night. The ride leader (sorry I forget his name) would make a suggestion of a hotel and book the number of rooms for those who wanted to stay at that motel. Other people stayed where they wanted. A couple of people dropped out during the ride, various reasons but none really related to the ride itself.
In some areas like Okahoma City for example there was only time to see a few tourist things. It came down to a choice of the Will Rogers Museum or the Memorial at the Federal Building. Each group decided on their own where they wanted to go.
Incidently, I did several European rides with Bike magazine while living in London and this is how they do their rides. They tell you what hotel the reservations are at and you ride your own route at your own speed, just end up at the hotel at night to share you experience.
I actually find this a bit better than the group rides my US club does. It's hard to keep 25 motorcyles together, and please 25+ people, on a ride.
Just my opinion. BTW - I'm plannning on doing this Route 66 ride again in a couple years with this group.