Rich nice report - To be fair to Rory & Jen it is a very well marked route.
A lot of Ultras you are reliant on your map reading skills alone, i guess the danger here is if you rely solely on the organisers markings and miss one then you are stuffed if you dont have a back up plan (i.e. map). Go try a LDWA event they have some intresting navigation at times
I have entered this raceas my first ultra for August 2012