Stayed at Emmanuel's apt for 2 nights with my mom in Oct 2013. Emmanuel is a nice and friendly guy who came by to say Hi before he left Paris for the weekend to see his family. The apt is clean, spacious and has nice amenities (comfortable bed, stove, microwave, washer/dryer, powerful shower etc). Location wise, it is on a quite street that is a stone throw away from Rue Montorgueil which has nice restaurants (French, Italian, Asian...), cafés, bakeries, fish stores, cheese shops, wine shops etc. From the apt, its a 15-20mins walk to Musee du Louvre, La Seine etc, 5 mins to Les Halles and about 20mins to Avenue des Champs-Élysées. Its a great place to stay and explore Pairs if you are looking for an area that is not touristy, quite and very accessible to the buzz of the locals.
Some things to note: 1) this is 2nd floor walk up apt (no elevators), hence it would be an issue if you are carrying heavy luggages or are less mobile. 2) The area around Les Halles (a major transport and shopping hub) is usually very crowded and and the streets above can be quiet at night. Crime rate is also rather high. We have bumped into fake policemen who tried to extort money from us and pickpockets. As with big cities, you'll need to be very alert.