Pros: The biggest plus to this apartment is the location. It is an amazing feeling to be walking down the winding alleyways of the Latin quarter and nestled between two restaurants to find the doorway to this apartment building. Next to notre dame, great restaurants, the marais, excellent base to explore the city. Also, it was sparkling clean and had a very well equipped kitchen. The olive oil and balsamic vinegar in the cupboards was a nice touch!
The cons: Not having any windows in the main loft area (there is a skylight in the living room and a window in the loft by the bed) meant that it was very dark inside all the time if the lights were off, kind of a bummer not to have any natural light, but if you're out exploring most of the time you won't really notice it. Also, the loft ceiling is really, really low, and the stairs can seem a bit perilous to get down, especially if you wAke up having to use the restroom in the night.
All in all, if you're looking for a great location and a base of exploring the city this place is for you. If you're looking for a place to relax and lounge indoors a bit more, I would probably look elsewhere.