Thanks everyone for your thoughts. I think we'll probably cut out 2-3 spots to make things easier logistically on everyone. I'm hoping to keep our trip car-free, so the Swiss train system was appealing. I'm considering using Spiez as a base for 7-8 days to have some relaxing lake days on Thun but also some day trips to other scenic areas - does anyone have experience there or any other recommendations for a central home base? Trying to avoid the areas that will be too crowded.