Couldn't agree more. Though I've taken only a single night train in my life: from Beijing to Xi'an.

While slightly pricier than flying, I had a bed and could freely move around the cabin. To top it off - anecdotally, though intuitively it holds - those who travel by train are less stressed than those travelling by plane, and therefore friendlier and open to conversation.

A great experience overall. I hope to do more of this in Europe.