Route-wise, wouldn't it make sense to go clockwise rather than anticlockwise?
This way those dark, wooded rutted lanes would be tackled in day light and the more open Oxfordshire/Bucks section with better visibility would be done at night.
I found those dark descents a bit unnerving, with poor visibility even with good lights
Obviously Tewkesbuty would be closing for business if placed at Km 260, but I am sure there are plenty of 24 h options around town.... or it might become a manned control.
Some minor benefits include the huge roundabout south of Swindon, no more need to go all the way around it mixing with motorway traffic, which also was quite unnerving for those of us getting there at "rush hour".
Thoughts?