>> Alpenrose, I have enjoyed your posts immensely.
Thank you, I'm glad you enjoyed them :-)
>> For the Grindelwald to Meiringen bus ride, would you suggest reservations (first week of Julyish)?
I don't think it's possible to reserve a seat: it's basically just a local bus, with people getting on and off at many places along the route. I took that bus twice from Grindelwald and once from Meiringen in September. The bus was crowded for one trip, with people standing for part of the way, so may well be crowded in July too.
To improve your chances of getting a seat, it might be worth waiting at the Grindelwald station bus stop well before the bus is due to depart, or travelling from Meiringen to Grindelwald instead of Grindelwald to Meiringen.
Apart from that, even if it starts off crowded at Grindelwald station, many people are likely to get off at the second stop (Firstbahn) for the gondola to First, and other people will get off at other stops within Grindelwald village.
If you do get a seat, try for one on the right-hand side when travelling in the direction of Grosse Scheidegg from Grindelwald. Although the twists and turns in the road mean both sides get good views of the magnificent mountains and glaciers, I think you get the views for longer on the right hand side!
>> I believe you also mentioned one time about upgrading from 2nd Class to 1st Class (last autumn trip reports) quickly through the SBB app. If that was you, could you walk me through the steps on the app?
Yes, I can do that :-) I might start a new thread for it though, so it can be more easily found.