From the Swiss Vignette site...
'A Swiss vignette is a mandatory road document that should be purchased by all drivers using the Swiss motorways and certain sections of roads subject to tolls. The Swiss vignette requirement covers all motor vehicles and trailers whose GVW does not exceed 3.5t.'
As we were in no rush this year we decided to use the ordinary toll free roads in Switzerland. I planned all our routes before we arrived. Yes it takes a lot longer but we had plenty of time so there was more time to enjoy the scenery.