Nicolas’ place is in a good and beautiful location in the center of Paris, very convenient.
Two negative points though:
it is directly on top of a very noisy bar and the windows are all single layered glass so you hear everything (don’t know if was because it was a weekend or if it is noisy every night)
The beds of the bedrooms were not very comfortable because the mattresses were old, stained and sagging.
Don’t know if those are important for you but for us it ruined our short stay.