Xavier was a great host! Our flight was a little delayed and he was very understanding when we advised that we'd be a little later than the agreed upon arrival time. When we got there, he gave us a tour of the apartment - explaining how things worked as well as where things were. He also had a tip sheet of where to go in the area (sights and restaurants) and public transportation.
The apartment is a short 3 minute walk to the metro station. We were there during the week so we didn't experience any weekend activities and the noise that could potentially come from that.
The apartment is in the Gothic quarter which means older buildings and lots of alleys. If walking through alleys makes you uncomfortable, I'd suggest looking outside of the Gothic quarter. We didn't have any issues and were very comfortable with our selection of Xavier's place.
Thanks Xavier for a great stay! :)