There are some aspects of this place that we liked a lot, and I think it has a lot of untapped potential. Unfortunately, the bright spots were heavily outweighed by the negatives, so I have to warn others to think hard about what they can tolerate before booking.
I'll start with the positives:
* The space is almost as unique, eclectic, and colorful as the photographs suggest (albeit, as others have noted, with far more explicitly sexual imagery than one might infer from the listing). We enjoyed the unique decor a lot.
* The location in Paris is excellent. It's easy to get there, and the location is convenient to shops, tourist attractions, and nightlife.
* Check-in and check-out went pretty smoothly (there was a slight delay before check-in) and Lionel et Lara were very responsive and communicative during our stay.
* The loft is very big for the price, so it's a good value for those who want lots of space.
Unfortunately, there are also many negatives:
* Cleanliness was a big problem. Many parts of the loft were covered in a thick layer of dust which greatly aggravated my allergies. There was moldy food left in the refrigerator. Almost all the glassware was coated in oily dust that the dishwasher couldn't fully get out. The sheets were oddly damp when we arrived and did not smell clean. The floor was so dirty that after 30 minutes of walking barefoot on it, our feet were pitch black. There was also evidence of rodents, although we were lucky enough not to see any. We spent most of our first day there cleaning just to try to make the space livable, and to add insult to injury the owners asked for hundreds of euro in additional cleaning fees after check-out because we'd used a lot of towels in the process.
* More things were broken than functional. The clothes washer/dryer aren't really useable because the washer's spin cycle doesn't work, so any items washed come out too water-logged for the dryer to handle. The clothes iron can't be used because its surface is chipped and will snag/damage any clothing you try to iron. There are tons of umbrellas, but at least the one we took with us on a rainy day turned out to be broken. The cool coffee table shown lit up in the photos is broken, along with about 1/3 of the lights.
* There are extreme restrictions on noise after 9 pm, which weren't stated in the listing when we booked. This isn't your typical situation of being considerate of the neighbors by avoiding *excessive* noise. The expectation is to maintain church-like silence after 9 pm. This is outside the owners' control as it's caused by an eccentric upstairs neighbor, but needs to be taken into consideration when booking. During our visit, the neighbor falsely accused us of throwing a party and later threatened us in the hallway after we played low-volume music on a small, battery-powered bluetooth speaker while relaxing at night.
* The place seems like an electrician's nightmare. Everything requiring electricity seems to be connected to long chains of extension cords. I'm not qualified to say if it's unsafe, but it was concerning to me.
* The steps mentioned in other reviews weren't a big issue for us, but be sure you are ready to haul your luggage up and down 70 or so steep steps before you book.
Overall, our experience was a negative one, despite the fact that certain aspects of the stay were excellent. If the owners could address the cleanliness issues and all the broken amenities, then this could be a cool place to stay for those willing to remain absolutely silent at night. Unfortunately, other reviews suggest that these are longstanding issues, so I wouldn't hold out much hope for their being fixed. It's a shame, because the place does have a lot of potential.