We had a wonderful time at Valerie's studio. She gave us very clear instructions on how to get into the building and was helpful in answering any questions we had quickly.
The building itself is very old, and we were worried for a second when climbing the stairs, which can be a little intimidating at first, but the apartment itself seems relatively recently remodeled and is very welcoming. The Mouffetard area is one of our favorites in Paris and this apartment is right on it. It's a very lively area, and fortunately this is located on the southern end of it which is less noisy at night, and it also has very good windows to reduce noise significantly. Overall this was a great experience and we would definitely stay here again.