This is a brilliant race - I've done it twice and hoping to do it this year.
Very much off road - there's just a bit of tarmac at the very start/finish, the rest is mainly sandy paths with a few rockier bits. Do-able in normal shoes, although I wore race flats to avoid turning my ankles.
Lots of climbs/descents, and a glorious view from the top. Shady forest, so well protected from sun & wind.