Excellent road, with great views. As others have said everything is cheap, no tax. We were extremely lucky and had naff all traffic and were able to enjoy the road over Port dEnvalira.
This road goes to Port DEnvalira, the highest road in Pyrenees. Great open corners but with lot of traffic. Cheap fuel, as rabbit said ;)
Some incredibly tight sections with nice width and good visibility, spoiled in places by the queues of cars near the borders and loads of fuel stations (i.e. risk of fuel or road), otherwise nice and a good place to pick up cheap fuel (40% less than in France)