Elena's apartment is in a great location, close to the metro station République. The plaza nearby has swing-dancing most nights and is surrounded by restaurants and cafés (including "Traiteur Libanais" for Lebanese food and the outstanding "Du Pain et des Idées" bakery). Check-in was super easy, particularly for someone like me who didn't have a data plan in France. And Elena was super helpful and responsive with all of my questions!
As a sidenote, the apartment is very small, as it's a "chambre de bon" (previously the maid's quarters). I was comfortable in the space, and I also didn't spend much time in it, since I wanted to explore Paris.