I was lucky enough to have some time on a business trip to San Francisco to ride in West Marin County. I didn't ride the exact route you described (I rode one I found on pashnit.com) and it was incredible. I think I hit more curves in 4 1/2 hours than I have in 10,000 miles of riding in Illinois. If you're ever in the area make the effort to get at least a half-day ride in.