Siena is one of my favourite cities in Italy. It is small and may not be the best if you are looking for parties or clubs, but it is an authentic Italian old city. If you live in the city centre the grocery shops and the gyms are small, but there is a “circolo culturale” where different workshops are organized. My experience in Siena is been very influenced by covid but I can see that restaurants and bars are gradually reopening and things are improving. “Opportunities” is not the word I would use to describe Siena, but “quietness, history and nature” represent it well.
As for the University, I had a pleasant experience. The professors are extremely prepared and the rooms are nice. There are plenty of places where to study and with your badge, you get free meals at the “mensa”.
My field of study in Linguistics. I am an Italian student, but I have one remark that might be useful about bureaucracy: if you are an international willing to study in Italy beware that you will be spending part of your time dealing with administrative offices which sometimes might be hard to reach. Be prepared!