My girlfriend lives in northern Germany and going around in Germany by train is just a big waste of time, because most of the time you have 0 signal as soon as you are outside of a city. For example traveling by train from Vienna to Bremen takes around 8 hours, but I basically need to stop working as soon as I cross into Germany. 0 Signal.
If you are in the Netherlands, Czech Republic or Austria and you cross into Germany it's like traveling back in time. Very often you are lucky to have some EDGE reception, while at the other side of the border you had high speed LTE.