That descent is awesome, three routes down, so if you keep to the right you’ll get to the steepest one, averages 1:4 on bedrock and peaks at 39% :). A great slide down from the top, you kinda ride over the edge and can’t really see where you’re riding apart form in a rut :). Loses over 600 vertical feet, though a couple of others lose 500′ of vertical. Its a bit like the Dyfi, but I would say steeper climbs (definitely – there’s a fire road climb that goes 1:5 and then 1:4 and someone recorded 1:3 for a short section!) and generally steeper descents.
Really is a missed gem, only started looking in there a couple of years ago when it became clear that bits of Nant may be out-of-bounds for a bit if the wind farm goes ahead.