I had a wonderful experience staying at Sandrine's place. It is perfect for a solo traveler.
The studio is in a quieter part of the city, very safe, and right around the corner from the metro. You are also within walking distance of the Eiffel Tower. The neighborhood has everything that you need and some great boutiques including many consignment designer shops which are quite a gem. There is a bank, grocery, and multiple restaurants right around the corner. I had no problem either walking to or navigating the metro to every place I went to.
The studio itself comes equipped with everything you need (except a power adapter). It is small but very comfortable.
Sandrine is a very warm host and easy to communicate with. We didn't get a chance to meet but she made sure that I was comfortable and answered any questions immediately. I would stay here again!