Here's a second for All Rivers. They did our shuttle for combined Main and Lower last August. Very helpful and flexible. They took our vehicles to Hammer Creek the day we were passing it in case we wanted to get out because of a big grass fire downstream (also made it easy to drop some stuff off in the cars) - we chose to keep going - no problem, we changed our time to get cars to Heller Bar (we talked to them at Hammer Creek, but could have achieved same end by leaving note in cars if they had not been there - they were going to check for our cars later to see whether we had decided to keep going downstream) no problems or hitches with the shuttle.
We planned for 17 days, kind of low water level, had a couple of antsy teens who wanted to take out earlier and we wound up taking 14 days total. Didn't have to push too hard to make our miles, but we had some fairly long days and never ran into too much headwind.