We (2 of us) stayed at Olivier's place for a week in the beginning of September. The location is top - do not expect views of Sacre Coeur of Eiffel tower, but the small balcony overlooks the St. Martin chanel and gives you a chance oversee the chanel boats (day) and the lively atmosphere at the banks (at night). A store is just steps away and if you're on a tight budget, buying drinks there and hanging out by the chanel is a great (and cheaper, but no less fun) alternative to going to one of the nearby bars.
Asthough we didn't see eachother, Olivier was a very helpful host, giving us directions and all the info we asked for.
The apartment, as the add says, is pretty basic (as is the entire building). Could be cleaner, could be renovated (would be both if it were mine) but on the other hand, it is charming and interesting and a very comfy place not just to sleep but also to spend a rainy afternoon (done that! A selection of movies and internet access kept us entertained).
Overall - just as the ad says: great location, basic apartment. Had a wonderful time.