The rooms are well decorated and the location is excellent. We did hear the street cafe noise in one room but it was not bothersome with closed windows.
Do note the steps up to the 4th floor.
We tried L'Escargot and the setting is great but the service is slow. But do try some of the excellent pastry shops nearby.
Non-smokers who are sensitive may have trouble. It may be temporary but it was pretty intense when we were there.