I did this one today. I parked the car and bike trailer at the village hall at Pakiri and then rode the bike to the start point a few kms away. I am a novice off road rider, but very experienced road rider. I ride a road legal wr250r.
Anyway the track is just under 30 kms in each direction. Mostly gravel. A few straights and lots of bends.A bit of road traffic but not much, just be aware on blind corners etc.
Overall I enjoyed the ride. Not technical really but plenty to get the rear spinning and the front squirming. The beach at the far end is really a cracker and was pretty busy when I was there (this is the xmas break
I recommend downloading the gpx file to your phone as there are a few times you need to choose which direction to go.