My opinion is based on a Master Studies at RWTH Aachen University, after having studied in the Netherlands and Finland.
The RWTH Aachen has good research facilities but the clear focus is there – not on teaching. Most of the system is “Do what you want – here are the main rules”, which leaves you without much help – either you have a lot of contact with other students that do the same or you will miss deadlines. I do understand this is a concept, but for example, missing centralized e-mails about when you have to enrol exams are not worthy of 2018.
Another thing I don’t like at all is that the initiatives of students are punished, not encouraged. If you want to do a Master Thesis on your behalf, do the research, have a company and topic ready, you may get told “But it’s your idea. This is not how it works”. I personally prefer the encouragement of initiative from students side.
Erasmus is something that the university should work on, outgoing and incoming. Outgoing because seldom the credits are accepted after, incoming because many subjects are not taught in English.
So, you can make it as easy or hard as you want. The university will give you opportunities IF it fits their initiative. Personal relations between supervisors and students are very seldom compared to the Netherlands and Germany.