I cannot say enough great things about Josephine and the apartment! As somebody who knows the city fairly well, I can tell you that the apartmemt is in the best possible location. The neighborhood itself is one of the best in Paris. A very "local" feel without many tourists, yet centrally located. Fantastic restaurants and shopping too, including Paris's best speailty food market, Le Grand Epicerie, and best farmers market, on the Boulevard Raspail, literally a few blocks away from the apartment. And when you wany to go to other areas of the city, most places are reachable on foot in 45 minutes or less, and there are many different Metro stations within a few blocks of the apartment meaning you can minimize transfers.
As for the apartment itself, it is extremely spacious (particularly for Paris), and everything is basically brand new. It is extremely comfortable and well decorated, and the washer/dryer is a great plus. It is located on the ground floor but on the courtyard rather than the street which it extremely quiet (the street itself is a side street so it is extremely quiet anyway).
And finally, as for Josephine, she was an incredible host. Before we arrived she was extremely helpful and communicative and gave great recommendations. And while we were there, she took care of any issue straight away, within minutes.
Overall, I could not have asked for a better experience! I would stay at the apartment again in a heartbeat, and I would highly recommend it!