Comfortable, large apartment. When you know the typical Parisian apartment, you realize you've found a gem. No elevator, but we're reasonably fit and didn't find that to be an issue.
Living/dining room and one bedroom are above street but sound insulation is excellent, noise wasn't an issue. Two other bedrooms are above yard. Parents of toddlers/young kids will want to be careful with the windows, especially in one room where a child could climb to the window from the bed.
Great location, convenient to everything in Paris with the RER/subway/taxi stop nearby. Steps from a small but well stocked supermarket, and a street packed with specialty grocery stores, including bakeries and pastry shops, cheese shop, charcuterie, fishmonger, etc. A foodie's dream!
Apartment looks like it's actually occupied by the owners, not an AirBnb-only property. Which I actually prefer, it has personality and avoids the "AirBnB international" style. It does mean that the closets are full so space to put away your clothes is very limited.
Overall a fantastic stay, I would stay there again with no hesitation.