Fantastic road! I mean first part is excellent: great asphalt, great landscape and very curvy! Second part (when you are in Italy) no good at all: lot of traffic and shitty asphalt but villages there are great!
First part is really curvy (I mean you will never be riding straight at all), corners are completely blind and improve your cornering skills a lot.
Second part (more or less after the customs) is a little more straight, but italian drivers, cyclists and tourists make it hazardous.