Rail travel in Europe is a national phenomena because it is heavily subsidized, and different nations are willing to spend more than others on their rail system

Rail travel in Europe is a national phenomena because it is heavily subsidized, and different nations are willing to spend more than others on their rail system, so don't expect a unified experience as you cross borders in terms of either quality, track maintenance, on-time performance, or comfort. Paricularly as you cross from West to East you will see a big difference.