Reservations in Switzerland are generally a waste of money. Swiss people don't book them and in the trains where they're possible, often only a part of the seats can be booked. In addition, October/November is not a busy period.

You could indeed consider to book the bottom 3. Cheapest to book these trains is tickets.oebb.at: €3 per seat. DB charges €5.20, with seat selection. You can also book for €3 and a few cents and seat selection on cd.cz, but you'll have to use bahn.de to see which seats you want, since on cd.cz you have to enter the carriage and seat numbers.

Yes, I agree - don’t bother with reservations in Switzerland. Totally unnecessary, and nobody local ever makes them. Even on the PE, it’s not necessary.

Berlin to Amsterdam is probably the most important one. I might do Munich to Berlin too, if I was certain of which train I wanted. They’re very cheap. You can get them for €3 each from ÖBB - choose reservation only here

https://shop.oebbtickets.at/en/ticket

If you have a connecting journey, I think DB works out slightly cheaper.

I doubt you’d end up standing at that time of year. Bear in mind also that with DB’s usual delays and cancellations, you might end up on a completely different train to the one you expected to.

Thank you both for the great answers - exactly the info I was after! We’ll save our coins in Switzerland, and book the bottom three on OEBB. No connecting journeys and not super time strict. Thanks again!

@imogenejs

Please note that the line between Meiringen and Interlaken is still closed due to flooding in August. You have replacement buses, but you pass is valid.

@imogenejs

Please note that the line between Meiringen and Interlaken is still closed due to flooding in August. You have replacement buses, but you pass is valid.

Oh wow thank you this is exceptionally good to know… I’m assuming this is pretty straight forward, we’ll be directed off at Meiringin onto a bus, will there only be one / all going interlaken? Is this a similar 30 mins to the train? 
 

IC817 Interlaken - Zurich doesn’t pass through Meiringen so is it just our one train affected?

I should have remembered this line closure… still until the end of November.

The replacement buses are in the timetable on sbb.ch. There's indeed a direct bus from Meiringen to Interlaken. The IC Interlaken - Zurich takes another route and is not affected. It doesn't fit on the narrow gauge :)

I would agree yes to the bottom three, especially Zurich to Munich that train is very busy or it least it was every time I used it this summer including September (it was compulsory reservation at one point through st margerethen due to works) also be prepared for delays on that route. At one point there was a 90 minute delay due to all sorts.

its an SBB train so the Swiss 40 minute delay rule doesn’t apply.

munich to Berlin is another busy route if you get the DB navigator app it we’ll tell you how busy they expect it by using little body icons 1 is empty 2 is busy 3 red means very busy I found 2 or more get a reservation.

booking tickets for a single train is cheapest €3 on ÖBB tickets app just set your discount to interrail and then reservation only, for more than one ticket DB navigator app charges €6.50 per journey ie multiple trains and both will send notifications.

hope that helps and enjoy your ride past the lake to interlaken and Lake Constance through Switzerland/Austria/germany.

@steve_newcastle 

The train Zurich - Munich consist of a SBB trainset, but SBB is not the transporter for the whole journey. It is a cooperation between SBB, ÖBB and DB. International rules apply if you travel in two countries or more, but internal rules apply if you travel only in one country. And Interrail/Eurail rules if you travel with these passes.

What do you mean with the Swiss 40 minutes delay rule?

The Swiss have brought in a law/rule that if a train from a non Swiss operator is going to be delayed by 40 minutes or more they won’t allow it over the border I am not sure where the reference for this is but it was widely known about by everyone over the summer. 
 

the only route I saw delays over 40 minutes on into and out of Switzerland was the Munich - Zurich - Munich route (this is the most delayed train in Switzerland) but as it’s an SBB train set it was exempt, I was on an Italian train that broke down on the way to Zurich but that only had a 25 minute delay.

ok the 40 minute thing as I understand it from Swiss people I met came from some negotiations in January and this is a report from July about it https://www.bluewin.ch/en/news/switzerland/more-and-more-german-trains-are-not-allowed-to-enter-switzerland-2304207.html

I never saw a train refused entry but everyone seemed to be aware of it everywhere I went in Switzerland.

@steve_newcastle 

The only non Swiss operators I know are EuroNight/Nightjet, all other day trains are cooperations between SBB and the foreign transporters. If the delayed trains are not accepted, it is an internal rule of the SBB and it is not stated in a law.

The problem is that ICE/IC from Germany entering in Basel SBB or Schaffhausen and EC from Italy are integrated in the Taktfahrplan. If they are late, SBB must organize replacement trains on time for Swiss customers and it is nearly impossible to find free slots later.

It is also often the DB who stops the late ICE in Freiburg (Breisgau) or Basel Bad Bf because the trains are needed for the opposite direction.