The downside here in Germany, the trains are very fast but then slow down to go to the city center (Munich, Leipzig, Hamburg + also too many stops in general fo

The downside here in Germany, the trains are very fast but then slow down to go to the city center (Munich, Leipzig, Hamburg + also too many stops in general for political reasons) - so it still takes a working day to travel around. As Amdahl's law applies here, newer high speed trains in Germany are no longer as fast, because if you have these slow passages / many stops, there is no difference between 250 and 300 (there are some prestige 300km/h lines).