I purchased the 3 day pass last minute on the night before traveling fo Jungfrau the next day. It was the best thing I did. I received the confirmation and voucher immediately on the app and via email. All I needed to do was go to the Interlaken OST train station and exchange the print of the voucher for the pass. The only problem was that pass mentions that it includes the bus in Grindelwald but the bus driver told us that the pass was not valid so we walked to First Bahn which is a 10 mins walk from Grindelwald Station. Their customer service is responsive which was helpful to calm my nerves at 11pm when I was trying to make the reservation.

We used the ticket most days for trips on cable cars & cog rail but not all cable cars are covered. Those we used did offer 25% discount if you had a Pass. Local Buses were not covered. We enjoyed our trips but not sure we got great value for money. However this is Switzerland everything is expensive....

This saved us a lot of money over just 2 days of travel around Interlaken and was very convenient to use as we could just get on the trains/cable cars without going thru the line at the ticket office every time. Only improvement would be to allow exchange of voucher at Interlaken West Bahnhof (as well as at Ost).