Booking and Communication were very easy. Claude is a very nice and funny host - even gave us an info booklet with his favorite spots in Paris, which are less touristic.
The Appartement is by foot 18 Min from Gare du Nord, 12 Min from Sacre Cour and 5 Min away from Moulin Rouge. The Appartement was clean and quiet, when the windows are closed. The weather was very hot - but there is a Ventilator :).
All in all a very good Appartement to stay for a few days!
Thanks for the stay, Claude!