TL;DR: Where would _you_ go out of these three - University of Saarland, University of Bonn, or University of Freiburg?

How would you go about evaluating different Universities for a graduate programme in CS? Apart from the content of the course, what else would you be looking for?

Some specific questions that I am trying to find answers for:

1. Are the research groups in the campus beneficial to graduate students? It seems like a post-doc thing at the outset. For example, University of Saarland has a rather limited graduate syllabus [https://www.uni-saarland.de/fileadmin/user_upload/master_portal/masterangebot/mathinf/informatik_mhb.pdf] but there are a lot of research groups [https://saarland-informatics-campus.de/en/forschung-research/research-groups/] in the campus. I wouldn't mind the rather limited course content if I would get to work with some of these groups. I have no idea if Msc. students get to associate themselves with such groups

2. Saarbrucken has a lot of independent research institutions like DKFI, Max Planck institutes e.t.c. If I'm a masters student, will I benefit from the presence of more institutes in the vicinity?

3. Thank you for reading so far. I've done a little homework and tried to objectively compare my options here: https://docs.google.com/spreadsheets/d/1YKzzR5OWs-U30j9YsiadMrCm74SL_R0dJ4SXI44gKMM/edit?usp=sharing

_Any_ extra information that can help me decide would be appreciated. Thanks :)

As of now, this is how I see things: Bonn > Freiburg > Saarland. But Saarland would easily be my top preference if graduate students would get to work with research groups - especially the "Cognitive models of human language processing" (Prof. Vera Demberg) team.