In short: great value.
I had a private room with a bed, desk, armchair and a big closet.
The house is modern and spacious, with all the necessary tools to cook meals, and some breakfast included. It was also very quiet and warm, too. I had complete privacy during my stay.
The apartment is located near two bus stops and 10 minutes away from the M1 metro line (less than 30 minutes total commute to EPFL).
Ingrid is an exceptionally polite host, very nice to talk to (she speaks perfect English) and was very accommodating.
Given that the stay was really cheap (compared to the prices in Lausanne), I can safely give 5 stars for the exceptional value!