Christine is a great host! I stayed in her apartment for two weeks and was very impressed by her availability (she lives right next door and answered any messages almost immediately).
The apartment itself it pretty simple--comfortable Queen bed, normal bathroom, basic living area, full kitchenette. The washer was very easy to use. Also, very nice view into the courtyard of the apartment complex (very typical Parisian old building style). You do have to walk up two long flights of stairs (both floors have high ceilings). Although my mom complained the apartment got cool in the evenings, I think it was ok.
The location is GREAT though, maybe 25 seconds from the Pompidou and three minutes from the Hotel de Ville metro station (from which you can get to pretty much anywhere). There is also so much to do around the neighborhood: I recommend stopping by the little traditional Patisserie around the corner (Rue du Renard and Rue Pierre au Lard). I ate their tartines aux epinards and pistachio merengues almost everyday. If you like theatre, make sure to stop by the Theatre de l'Essaïon and the Theatre Cafe de la Gare--both put up multiple small plays every afternoon and evening. If you like cinema, the Pompidou screens a couple of arty films and documentaries per week; there is also a more mainstream movie theatre about four blocks away (the mk2 Beaubourg). Next to the mk2, there is a delicious crepe stand (with 2-5 euro crepes)! For groceries, stop by the Bio c'Bon on Rue du Renard for organic and gourmet foods, or go to the Carrefour City one block further down.
Clearly, there is a lot to do.
Overall, I had a nice stay.