Porte and Placette
I rode Col de Porte via Quaix and Sarcenas (then down via St. Laurent du Pont and Placette) today. The 59km route takes you up and over col de Porte, along the beautiful D520b, and back via the well paved col de Lautaret. (although by that point my legs were starting to wane a bit and I was unable to fully appreciate the new pavement). It climbs 4400 vertical feet/ 1340 meters total and has three sub-climbs: the road up to Quaix, the climb up from the Vence river to Porte, and the final mini climb up Lautaret.
It felt pretty hard: probably harder than the clockwise version. They are not exactly the same ride in reverse (last time I descended port via Sappey and col de Vence rather than Sarcenas), but *almost* the same.
http://www.mapmyride.com/route/fr/fontanil-cornillon/820128310532227898
My average speed was 13.2 mph and I completed the ride 20 minutes faster than the clockwise route, despite lower average power (but 0.6 mph higher average speed -- maybe the wind played a role?).