My second attempt at this route, my first was back in December. As predicted, much quicker without the mud, but still tricky in places with a lot of the fields overgrown with brambles, generally a pretty tough section every 10KM or so, probably 3 x 1km sections with chest height brambles!
Managed to remember where the dead ends were and miss out the doubling back! Still the route is about 2km longer than the original GPX because of the work arounds.
All in all was a very comfortable morning, great weather, started just before 6am and finished just after 1020am, so route wasn't too busy.
I think, supported this could easily be a sub 4 hour route, would just need a refill of water at around half way and you could really push the first half for sure!