It was a pleasant stay. The location is extremely convenient, next to several metro stations and just a couple of stops from Gare de l'Est and a short walk from the Enfants Rouges market. Johanna always replied quickly to my messages. The place was clean, it looks nice and it was very quiet. Overall it was a great choice for me.
A few simple things that could have made it a 5-star: Providing an extension cord when I asked for it (no outlet near the table, where I needed it for the laptop and the extra heater); adding a (washable) rug to the cold floor. Having simple things like salt, olive oil, and a coffee maker for real coffee in the kitchen.