My experience
I decided to apply for the Cours de vacances program in Lausanne because I wanted to improve my spoken French before finishing my French major. I can't recommend this course enough! The practical language courses were lots of fun, and the teachers at the university were very engaging. Although there were a lot of other Australian students, there were also lots of people from other countries, many of whom didn't speak English very well. This meant there were plenty of opportunities to speak in French, and I definitely felt that my confidence in speaking improved heaps. Lausanne is a really fun city to live in, and it's very close to all the wonderful things Switzerland has to offer (including spontaneous ski weekends). I would advise against booking accommodation through the university (it was in a hostel, and very expensive for what it was). I stayed in an Airbnb with three other girls from UQ, and came away with some amazing new friends.