I loved this flat!!!
It is literally a block and a half from Opera in the center of Paris. The apartment is on the 5th floor (there's a lift), and is owned by Antoinette and her son Stefan. The room on the top floor was great, I had a fantastic view of the Parisian rooftops during the day, and the window opened up nicely to keep a nice breeze coming through (end of September). During my stay in Paris it was upper 60s-lower 70sF, a couple of days it rained and for a little time it was very humid, but throughout all of the temperature changes the room remained quite comfortable. My hosts were nothing short of extremely nice and friendly, as was their little dog that probably barked twice in the 4 days I was there. The apartment has two bathrooms to bathe in, but one toilet (downstairs).
I would say that the photos on the listing for this apartment don't really do the place complete justice: what I really liked was how the apartment was decorated, it really made me feel at home, and Antoinette being a jeweller has a lot of cool taste in the pieces the flat was adorned with.
Basically, for the price and the location, you will not find a better value in Paris. Being located a 2 minute walk from Opera, if you're flying into Paris there's the Roissy bus that literally goes directly there for about 10 Euro I think; the trip was much nicer than having to take the subway metro. If you're coming from Gard du Nord, it's about a 25 minute trip by metro... from Opera you can access every part of the city with an equal amount of ease since most of the metro lines either intersect directly with or just a couple of stops from that location.
As long as they're on Airbnb, I could not imagine renting anywhere else without checking in with Stefan and Antoinette first.