We LOVED Isabelle's place. It is incredibly convenient in terms of being next to the Republique metro station which has many lines that can take you anywhere in Paris. A great grocery store is just opposite the building. The neighbourhood is safe and has many nice restaurants and bars within a 5 minute walk. Marais is also close by and a great place for shopping over the weekends.
The apartment itself is the perfect size for a couple and has everything you could possibly need. It was clean and comfortable, and incredibly quiet since it overlooks a courtyard and not the street. We slept very well and only woke up with the nearby charming church bell at 9 am which was a wonderful alarm clock. The stairs to this first floor apartment were easy to negotiate.
Isabelle was great at communication and the check in and check out was very easy. Overall we can not recommend this place enough. We looked at many other options in terms of locations, price and size but were so happy that we settled on this amazing 'home' which made our entire trip that extra bit special. Grab it if you can immediately. We hope to come back one day as well.