The apartment was very clean and comfortable. It's a small studio, but for one person it's great. It's right in the thick of things in a great very lively neighborhood with LOTS of bars, restaurants and clubs. The location is very central with lots of access to the Metro and walking distance from many important sights. Nevertheless it's on a quiet small street (for an urban environment). You won't want to spend a lot of time in the apartment in Paris anyway!
Joseph, the host, was very nice and very helpful and communicative. He met me when I arrived and explained everything, and sent me an e-mail during my stay to check on things. Overall I'm very happy with my stay and look forward to a future visit.