Guillaume' apartment is great. My mom and I stayed here for 3 nights. Guillaume greeted us to check us in and gave us tons of notes and recommendations for the city. The apartment had all amenities you would need. He even had bread, butter, jam, milk and espresso for us.
The only note I would give to future guests is that the apartment is on the "1st" floor, however there are two flights of stairs to get to the first floor. This was not a problem for us, but incase you can't or don't want to climb any stair that's the only note I would have. Everything else was wonderful.