I lived round the corner from this road for 7 years in the 1990s and it was absolute heaven on my NSR250 and then ZXR400. Best done on a weekday as it gets a bit touristy at weekends. This is the most enjoyable road Ive ever ridden. Just look at the shape of it on the map!
Fantastic curves and mountains with light traffic all the way. The best section is once you get on 311.