My experience riding trains in Europe as a European is that everything is great when you're traveling domestically (bar the usual complaints from any commuter that exist but differ between any mode of transport) but once you take a train that crosses a border things really fall apart. Especially when it's not some commuter line.

That's one thing I wish the EU really did better - do more to integrate and de-federate the rail systems. There should be no major difference riding the rails in any state. Of course, this is a lofty goal since even within countries usually commuter transport is run by local companies and not even nationally interoperable.