Charlotte's flat is perfectly (!) located, near the well-connected Place de la République and the upcoming neighbourhoods of Canal St-Martin, Oberkampf. The flat itself is tiny (probably average for Parisian standards) but nicely arranged, the shower is very comfortable.
Unfortunately, there's a noisy child on the flat above this one, and isolation is pretty bad. He likes to run and scream. Just be aware you might be waken up quite early, but if you plan to wake up early anyway because you want to enjoy the huge cultural offer of Paris, then it's fine I guess.
Charlotte is nice and quick to answer.