The biggest deal with the Agnès place is the location. It is in a awesome spot of Paris with easy access for all main areas of the city. I usually stay in Quartier Latin and I am familiar with the surrounding. So keep in mind that the place worths because of that.
The place is small not very well divided but it is due to the profile of the building. Even thoug the architect managed to create a comfy space with a lot of style and even on a tiny bathroom (wich is always a problem in Paris). There is a regular shower instead of the usual bath tube and I find it great.
The space for cooking is minimal even for preparing a small breakfast, so do not count on it to prepare real food.

The cleaning on the place was ok but the shared premisses (access corridor and the flight of stairs to 2nd floor) were dirty and not well illuminated.
The bed is comfortable and there are curtains to block the sun in every window.
It is importante to note that that the building is above a subway line and you can hear sharp and clear every train that passes by every 5 minutes. It can be annoying when you is trying to sleep by night or even in the morning. After I slept it was not a problem.
There is a sound system on the living room and the bathroom where you can plug your phone and hear trough speakers on the ceiling but there is no TV.
I believe and have suggested that a TV might be a asset to overcome the noise from the subway. And this is the only place since I started booking homes on airbnb that has no TV. This is so peculiar that I was oblivious to it when I booked.
There are previous comments here about the smell of smoking but I have not smelled it at all.
Considering all of that now I think that the place is overpriced on itself but it worth due the location.
Agnes was very helpful on letting me drop the bags prior to check-in time. She was very king at all times e everything since the reservation was smoothly.