I have taken the buses neckervd talks about from Meiringen, half hour from Interlaken-Ost by train - and to me this is a great way to access the Glacier Express route in Andermatt - and shortens a bit the long train ride Brig-St Moritz. Stay overnight in St Moritz. Buses only run I believe about June thru September - I showed up at Meiringen once in mid-September and was told the bus was cancelled due to highway passes being blocked by snow.

A thrilling bus ride up and over the Susten Pass - I will forever remember that bus ride because a bunch of orthodox Jewish high school kids were on the bus and one had a bike and got off at the top of the pass and cycled down to Goschenen!

If you have a Swiss Pass it is valid on these buses but there is or was for me a few years back a 10 or so Swiss franc Alpine supplement.

And those buses do stop for a half-hour at a big damn on top of the pass - can get out and feel the Alps!

thanks to p. and n. for the deep info... i really have been a bit lazy with travel arrangements this time... and the trains are already booked, so i'm sort of glad that i can no longer obsess about it. the laziness has been due to sticker shock at the room prices in switzerland (against the u.s. dollar)... have used up all my late night energy trying to find rooms that are within our budget. even airbnb has largely disappointed... but most rooms are booked (except one that cancelled today) and am just happy to be done with that planning. now just a few late (into early morning) research bouts with restaurant recommendations and i'm ready to start packing. thanks again for all the help here.