We are using Zurich as our stopover point en route from the US to Johannesburg in August. At the beginning of our trip, we can either fly in to Milan or Zurich arriving at 8 or 9 AM day 1. We then will be flying out of Zurich at 10:30 PM on day 3. So we have 3 days and 2 nights to work with then.
On our way back, we arrive in Zurich at 6 AM and then can fly home the following morning either from Zurich, Geneva, Basel, or Milan, so one day/night then.
I am traveling with my older parents, so we won't be doing much in the way of hiking; however, they are in good shape without health issues, so their travel endurance will be decent. They have always wanted to do a scenic rail trip in the Alps, so I am trying to incorporate the Bernina Express and/or the Golden Pass. They are more interested in seeing beautiful mountains views than a city, so we plan on skipping time in any of the larger cities other than passing through on our way to/from the airport. Although I will be returning on future trips to do some hiking, this will likely be their only trip to Switzerland, so I want to make the most of our brief stay.
Suggestions on our best routing and use of time given the above options? Many thanks!