This section of the D81 is reckoned by some to be the finest biking road in Corsica. For me, it was good but from a purely riding perspective I prefered some of the roads on Cap Corse further north.
Whats great about this road is its combination of dramatic scenary (it runs along a jagged coastline before going through a beautifully eroded granite area, one of Corsicas most famous attractions and a UNESCO site) it has nice predictable corners on a good surface around the granite cliffs. At Piana the road narrows and is full of tourist traffic.