The location was fantastic. You're in the middle of everything and there are lots of little bakeries and shops where you can get necessities. We were allowed in early to drop off our bags while the room was cleaned, which was nice. The building was safe; you had to use 3 keys to get to the room. It seems like a quiet building too.
Unfortunately it just wasn't a great room. The stairs to the lofts are painted and slippery. There are no lights in the stairwells or halls and night, and being a typical Paris stairwell, it's tricky. The room the sofa bed is in is exposed to courtyard light all night, making it hard to sleep. There was food and medication left from the previous person who stayed there. I accidentally knocked over a cheap lamp (it had a basic plastic clip) and it broke. I reported it right away.
We left the room very clean, stripped all the beds, washed the dishes and wiped the counters and sink. Nevertheless we were charged 40 euros for the lamp.
My first 3 star review but I feel it's fair. If you're 3-4 students and don't mind hostel-level accomodations, in a fantastic location, then this is the place for you. Don't lose a single spoon though- there will be no consideration for you, regardless of good a tenant you are.