The apartment in itself is great, really well decorated, has great location (République métro station is nearby, as well as grocery shops, Biocoop organic shop etc.). Fred was very nice and accommodating regarding arrival and departure time.
The acoustic insulation of the apartment is sadly very bad. There is a restaurant in the building and the back of their kitchen is in down in the courtyard; I could hear them emptying dishes, working, singing and talking until 23-24:00. They are not so loud but the problem is that the apartment is just above.
Besides, in the bedroom, I could hear the neighbors talking as if they were next to me in the same room. Again they were not excessively loud, but I could distinctly hear them talk, sing, play guitar, take a shower, go to the restroom etc.