The apartment is very nice, clean and in a great location in the heart of the Marais with a beautiful view on the typical Parisian roofs. Close to bars and restaurants and minutes away from different subways lines. Communication was quick and I got detailed instructions to reach the place. Just remember it's on fifth floor with no elevator and internet is quite slow but overall I had a very good time there.
The thing I really didn't like is that just before arriving I've been asked if I could shorten my stay by three nights and I accepted without checking (my fault) that I was going to a get a refund equal to roughly two nights, so not only I had the trouble to find and move to another accommodation but also got less money than I should. Therefore, beware if you get a similar proposal.