I wish I was notified that there would be construction going on during the stay. Was woken up with construction noise the first morning. Other than that, everything else was great. Nicolas was super responsive and let me leave my luggage around noon. If you need a place to kill few hours before checking in, there's a coffee place called "Anticafe Beaubourg" down the street. They charge you by hour (~5 euro) but provide free coffee/snack/wifi, books and boardgames. It's like hanging out at friend's apartment.
The apartment location was perfect. It's literally 10~15 minutes walk to everything. La Marais is a lovely neighborhood with bars/restaurants and shopping. There are also few bars on the same street. I highly recommend this place for its location.