We had a very good experience of staying at Jean-Marc's apartment. It is exactly as described on his page. Very good location, close to metro, and very near to main attractions in Paris.
Apartment is very comfortable for 4 people (really loved the comfort of sofa-bed). It is clean, very well maintained and has a good ambiance.
We couldn't meet Jean-Marc personally, however he was constantly in touch with me through phone, and his friend Pierre was very helpful and welcoming.
As we were staying here during the very unfortunate Paris attack time, hosts were very supportive and made us feel at home. They did all they could do to make us feel safe and homely.
I appreciate their concern for our safety. Both Jean-Marc and Pierre are very warm and welcoming hosts. I couldn't have asked for more.
This is highly recommended. If/when we visit again, will surely look for this apartment again :)