Juliette's apartment is in the gorgeous 6th arrondissement. St. Germain is just around the corner, and the flat is flanked on all sides by the best chocolate shops in Paris. Alain Ducasse has one of his bean-to-bar shops a block away, and the famous Debauve & Gallais is just outside the door. And not just chocolate--the Musee d'Orsay and the Louvre are all short (10mins) walks away.
The flat itself is cozy--the perfect size for a single traveller. I slept like a log on the comfy bed, and in the morning, enjoyed all the light that streamed in through the windows. As Juliette notes, the bathroom is outside the flat in the corridor, but I never found this to be a problem.
More than anything else, Juliette made this such an easy place to stay in. Though we didn't end up meeting in the end, she was a great communicator, giving excellent instructions and directions. She even made sure to check-in and see if I was doing alright.
All in all, this is a great place for a single traveller in the heart of Paris.