Thanks to Dakman for posting of this very detailed route description- it is almost like he was writing while biking.

I have ridden the Sattellegg climb on dozens of occasions and generally believe it to be relatively traffic free- I have had a few occasions of riding the whole climb without being passed by a car. However weekends can be less enjoyable with our motor powered 2 wheeled firends buzzing by.

I would add that after completing the descent from the pass, a more enjoyable route back to Zurich/ Pfaffikon is to ride on the road around the Sihlsee. This option has less traffic and very smooth roads. To do this, take a right at the big white church in Willerzell and then take another right, which allows you the option of skipping the bridge over the sihlsee that Dakman mentioned. You end up in the same place, having added 5-10 minutes to your ride in total- on the way to Biberbrugg and the Sihlsee.