It's a good 'un alright. I did this last year, fantastic race, great views. I'm hoping to do the full race this year. The route wasn't marked up through the quarries, I managed to tag behind an Eryri runner. It can be a bit confusing. The descent from Glyder Fawr down to Pen y Pass definitely needs a recce.
Remember to take a couple of quid for the bus back from Pen y Pass.