And even at 4 hours, things really depend: I just travelled about 650km from Berlin to Mannheim in about 5 hours. There’s no airport at the destination, so I’d

And even at 4 hours, things really depend: I just travelled about 650km from Berlin to Mannheim in about 5 hours. There’s no airport at the destination, so I’d have to fly to Frankfurt and continue from there. There’s a direct train every hour and considering time to the airport and check-in etc, taking the train is still faster. Air travel wins out on short/medium distances only if both ends of the leg are close to an airport.