Our first draft of this trip had six cities: Cologne, Amsterdam, Wengen, Venice, Florence, and Rome. On paper, it looked amazing. In practice, it was a trip where we'd spend a scary amount of time packing, checking out, finding platforms, and unpacking.
So we cut Amsterdam and Florence. Both are wonderful. Both are still on our list. And cutting them was the single best travel decision we made all year.
The "half-day tax"
Every time you change cities, you pay a tax of roughly half a day. Check out, get to the station, ride the train, find the new place, figure out the neighborhood. Even with great trains, it adds up fast. Six cities in a couple of weeks means you pay that tax five times. Four cities means you pay it three times, and you get those days back somewhere you actually love.
Where the time went
We gave the extra days to Switzerland and Venice, the two places we were most excited about. That meant enough nights in Wengen to gamble on good weather for Jungfraujoch, to ride up to Männlichen, and to just sit and stare at the mountains. It meant Venice after the day-trippers leave, which is a completely different (and better) city.
Weirdo rule of thumb
When you're building a rail itinerary, pick the two places you're most excited about and protect them first. Then add cities until the plan starts to feel rushed, and take one away.
So, Amsterdam and Florence...
You're not forgotten. You're just next.