My stay at Helene's flat was excellent. The apartment is in a central, if slightly bohemian, location. I was there when many Parisians were on vacation so I imagine it might be more lively at other times. In any case it's a safe area with fantastic Metro (subway) access 100 feet/30m from the apartment building.
The flat itself was as described-no problems with Internet or TV or anything. When there was a problem with the washing machine, Helene and her friend Max were very responsive and helpful with getting the issue resolved. The bed was comfy and the airflow good enough that no AC was needed (not that any place in France has AC!). For an affordable, central location in Paris, I would highly recommend Helene's apartment, and would certainly stay there again next time I'm in Paris!