Did it both ways. Best is east to west with a view of the Picos ahead. Some lovely open sections, great scenery and some tight bends.
Roads is mainly well-maintained.
It's about an hour and well worth it.
3 small passes finishing up with the most spectacular view of the Picos and La Hermida, just turn east at Pineres 43.241567N 4.561408W to find the viewpoint. 500 meters above the road and river below, the peak across the road is 700 meters above it.