We stayed in Julien's place for four days and thoroughly enjoyed our time in Paris. We regularly travel abroad, leveraging airBnB to find a place to rest up in the evenings so we have a good sense of what to expect for European lodging.
The good:
The bed is extremely comfortable and the unit is quite dark in the mornings, so it's easy to get a good nights rest. The location itself is on a busy street vs. a smaller/ quieter Parisian street, but the unit itself isn't too noisy. The street leaves a little to be desired, but there is a cafe nearby, a franprix and a patisserie/ boulangerie. Pretty much everything you'd need to run out for a quick coffee or croissant, etc. The digital check-in/ check-out process was also extremely convenient and the double-gated entry in to the inner courtyard made us feel quite safe.
The bad:
That said, Julien's unit was a a disappointment namely due to the wear and tear of the furniture, and really, the cleanliness overall. The photos present a unit that is clean, simply furnished and well assembled. Reality however is that the bathroom is quite dirty with black mold growing throughout nearly 65% of the visible grout. The rug does not match the photos and the furniture quite worn. The arm of the blue couch is visibly black and dirtied from who only knows what. Also, there are quite a bit of extraneous items around the apartment - drying racks, ladders, vacuums, etc. so the unit itself actually feels smaller and less put together.
If where you stay isn't a deal-breaker, then Julien's place may be a good option for you. For us, it needed a good scrub to be able to truly relax. I'm honestly not certain if the owner has recently visited the space. If he/she had, then I'm pretty certain it'd be a in a better state.