If you are hesitating even for a moment to book this room... don't. Yes, it is small, but there is so much to do in the immediate area, you will never need to be in your room. And even if you are, there is a nice table with plenty of seating and the beds are easily used as seating during the day as well. The room was quiet- there isn't a view because it overlooks a courtyard, but that also means no city noise. The price was by far the best we found and to be honest, that made me wonder what the catch was. There was no catch at all. The room is worth the price and more.
We had three adults- my father used the double bed, I was on the bottom bunk and my son used the top bunk. The sleeping arrangement would be good for a family with kids as well. There is a grocery store right around the corner and the room has a microwave, sink, warmer, and dishes with utensils as well. It would be very easy to stay here and be on a budget while in Paris. However, even if budget isn't an issue, it is still a nice place to stay to enjoy one of the nicest locations in Paris.
Our host was there to greet us when we checked in and communicated almost immediately when we had questions. If you keep in mind it is not intended to be a luxury penthouse in Paris, you will be very happy with your choice. I recommend it highly.