Very good location with lots of great restaurants close by. You can get to most parts of Paris pretty quickly from the apartment. The apartment is clean and has everything you need. It's nothing special but the quality/price ratio is perfect. Great choice, if you want to spend more of your travel money on great food, shopping in Marais or drinks in the evening.
PROS: Very well located in nice neighborhood, easy to reach by train, convenient for both work and leisure. Our host (Renaud) had sent very accurate directions in advance, and was very discrete. The studio was well cleaned and equipped (internet, iron, clean towels). The place is perfect for exploring Paris by walking and metro! CONS: The studio overlooks the internal yard of the building and the building is a bit "noisy" throughout the day (and some nights). Also, we happened to be around during the warmest days (>30oC) and the windows had to be open which didn't help with the noise. As for the heat, a fan would have been helpful, but again with such temperatures in Paris only air conditioning would work.
We loved our stay in Renaud's home! The location could not be more perfect - the home is about half a block up from Rue Montorgueil which offers every little shop, cafe and entertainment (and Starbucks!) you could ask for. It is a 10-15 minute walk to the Seine and all the action of the city, or a main metro/RER hub is literally at the end of the street if you don't feel like walking. This home was a perfect place to experience all the action of Paris, but have a quiet and comfortable home to return to. The only negative was that it gets very warm in the apartment. But, it's hard to be critical of that as most places in Paris do not have AC and it certainly would not keep us from staying there again. Renaud was very gracious and easy to work with. He is a great communicator and very responsive. We appreciate you, Renaud!