I've done it two or three times with a pillion, and, by the grace of god I've not had any issues. The first time I did it, I was with some friends and as we were going downhill towards one of the more extreme hairpins and elevations we had some classic cars coming up the hill towards us and we had to stop and wait on the slope whilst they negotiated the hairpin, some of them got the line totally wrong and and had to go into reverse to bring the front of the car in the right direction to get round the corner.