A really great experience. The flat is in a great location in a very chic area of Paris, a short walk from many of the sights.
The flat is a good size for 4 people, although one of the beds is perhaps a bit small for 2.
We didn't spend too much time in the flat, as we preferred to be out and about in Paris. If you are going to spend a lot of time there as 4 people, it might feel a bit small -- 1 sofa and a chair in the 'living room.'
We didn't use the stove, just the fridge and the water kettle and coffee makers. The flat worked well for our family for a week-long stay. We would definitely recommend this flat as a place to stay. We've had some excellent and some less than great experiences with AirBnb; this one certainly was among the 'great' ones. Highly recommended.