the place is really ideally located and yet very quiet. Smooth check-in and check-out process.

Pro:
Location, location, location! many bars and shops nearby, walking distance to many touristic places.
Really quiet, no street noise whatsoever, only once heard the neighbours coming home late and chatting in the stairway but that can hapens everywhere.
Smooth check-in and check-out process, Alex offered to check-in late (as we arrived after 10pm) and also let us stay later on the last day.
Very large master bedroom (for Paris standards)
Individal heater in the rooms and bathroom. Microwave. Host provided drinks and fruits and even an iPhone charger ;)

Cons:
We had to kill dozens of flying (food) bugs for the 3 days of our stay.
Bed linen in the bedroom smelled very bad because the linen were put on clean by the cleaning service but still wet and did not dry correctly.
Both bed and sofa bed are very very very firm.
Overall rather nice experience except for those downsides, but the place could be a jewel if only it was maintained better.