"My stay abroad was the absolute highlight of my time as a student".
After two intensive "Opening Weeks" with getting to know each other, bowling, ice hockey games and much more, there was a student party every Wednesday in the student pub Trossen on campus. Approximately every 3 weeks there is a huge university party in Karen (cafeteria building). Gävle is not the centre of the world, but the people there are great.
If you get to know a bit about Sweden, you'll find out a lot about other traditions etc. The city itself is not very spectacular, but the starting point for travelling is great. Other places in Sweden, Norway and Finland are easily accessible.
The student council is very active. We had student parties in Gävle on Wednesdays, a big university party every few weeks and occasional events such as a games weekend at the university - there was a lot on offer and a great atmosphere. There is a sports centre 500 metres from Campus Sätra (where we lived) where you can rent all kinds of sports equipment free of charge and flexibly. They even have camping equipment such as tents, sleeping bags and cookers.
For students of the Universitiy of Gävle there is a free ticket contingent for Brynäs ice hockey games (a traditional club, probably the HSV of Sweden).
In general, you should expect to spend about 2/3 of the time compared to German lectures. While there is a lot of frontal teaching in Stuttgart, Gävle emphasises individual learning: reading papers or book chapters, writing seminar papers, small project work, etc. Even lectures with 6 ECTS have an average of only 90 minutes per week, usually without compulsory attendance (varies greatly depending on the module). There was a strong focus on seminar papers and projects and occasionally attendance in seminars with discussion, but then usually with pass/fail grading. The 27 ECTS in my semester were almost a no-brainer. Most Erasmus students found the University of Gävle much easier than their home university.
We were accommodated at Campus Sätra -- a very multicultural environment just outside Gävle. I had a one-bedroom flat with my own kitchen and bathroom, which was very pleasant. I paid about 420 € including electricity, internet and heating for about 35 square metres. As the Swedish krona had plummeted, it was only about €380 towards the end of the semester. However, when you apply for a room, you can indicate that you would prefer a cheaper flat - then you will get a smaller flat. The size is not necessarily decisive.
The stay was the absolute highlight of my time as a student - if I could, I would definitely do another stay abroad!