Europe: By Train or by Plane?

I love train travel. If I can choose between a plane and a train, I’ll choose a train whenever I can. It makes the transition from one place to another a gradual one, with plenty of time to watch the world go by (to say nothing of the deep nap the train puts me in). And for some trips the travel time can be about the same, or close enough, once you factor in getting to the airport an hour …