Pros: Amazing location, good space.
Cons: Basement has a musty smell. The shower leaks, and fixtures were falling off (toilet paper holder, towel hooks).
The loft was quite comfortable, but my friends in the basement complained about there being an odor/moldy scent. Also, the shower does not do a great job of keeping water in, so strategically placed towels are a must. Lastly, the loose fixtures in the bathroom also need some help, and contributed to a somewhat "cheap" feel.
We interacted primarily with Aline, who was very responsive, and happy to address the issues that she was able to. The location is great, extremely close to one entrance/exit of the metro, and right in the middle of the Marais. You're less than five minutes from great food, and a 10-15 minute walk from major Parisian attractions. Definitely recommend this for two people, tentatively for 4, depending on how sensitive people are.