Studying in a palace is great, and the university facilities are also good.
The life in Mannheim is pretty good as everything is concentrated in the centre at a maximum 20 min walk from the university: shopping malls, restaurants, bars and clubs.
There is plenty of choice regarding your curriculum and which modules to take so you can personalise your semesters according to your preferences.
It is very competitive regarding grades and the exams tend to be long and difficult.
Overall, I’m having a great experience and thoroughly recommend.