AtagibaLink opens in new window. Hello Rodrigo Greetings from Switzerland. Personally, I would not recommend the Swiss Travel Pass Flex as it is rather expensive for its value. It might be different for the 15-days STPF, however. A travel pass is useful if you can be certain that you would spend at least its daily equivalent value on full fare tickets. This means a rather extensive use of the public transit for the activated travel day. I would rather opt for the Swiss Half Fare Card. Do you know that offer?
https://www.sbb.ch/en/offers/swiss-half-fare-card For example, what concerns your Jungfraujoch trip, the STPF grants a 25% discount for Jungfraujoch tickets while the SHFC grants a 50% discount. All in all you have to do the maths and work out a spreadsheet to compare costs. It also depends on the plans you have on that day. Of course, the STPF will simplify the ticket purchase which is almost zero to none, except for some mountain excursions. Yet, there might be days where you would spend less when purchasing single tickets compared to the per-day cost for the STPF. The fastest way to reach Jungfraujoch is Interlaken Ost → Grindelwald Terminal (Eiger-Express) → Eigergletscher → Jungfraujoch. You can also travel
Interlaken Ost → Grindelwald → Kleine Scheidegg → Jungfraujoch OR Interlaken Ost → Lauterbrunnen → Kleine Scheidegg → Jungfraujoch. Well, the seat reservation is not that new anymore. It is now the second or even the third season where it is in place as they are suffering from overtourism. And, bear in mind: the weather in Switzerland is not predictable more than 2 days out. We do not have sunny days every day, thus, you should not purchase the tickets too far in advance. In case of bad weather you will see: nothing. It would mean a costly undertake to simply experience cold, foggy, windy - say, unpleasant weather. Kind regards,
Roland