First long trip is on the books...
I will say that I was facing an unusual amount of headwinds on this trip -- which can be seen at www.hint.fm
When the winds subsided I got a full tank measurement and that gave me roughly 5-6% improvement in fuel consumption. I have never broken 8mpg with this rig while towing and I was at 8.5 for much of the tank and it dropped a bit at the end due to rush hour in-town driving.
There will be more trips to show more data, but they have been pleasant to ride on.