It's amazing how an experience can be affected by how it begins. Unfortunately, my check-in experience was sub-optimal as the instructions were not clear and, for about an hour, it started to look like I wouldn't have a place to stay.
Eventually, I had to call AirBnB support and, with their help, I was able to get in touch with the host and get the instructions about how to get in. So, my advice is, if you are staying here...be 100% clear WELL in advance about what is going to happen when you check in.
The location was great and the building was nice. The loft is small, but it was fine for me. The stovetop was broken when I got there, but that was fine since I didn't use it. The things of which to be aware are
1. the shower is very small and will take some maneuvering. Totally works, but you'll have to manage.
2. the ladder up to the loft is not easy on your feet. You're climbing up metal. If you're not ready for this, you're either going to sleep on the couch or not in this rental
3. if it's summer, the loft/bed part gets really warm. I opened the windows, which helped a little bit, but a nice touch would have been to have a fan up there.
I will give a lot of props for the decor. It has a very artsy feel and is quite welcoming. The window/doors open up (though the street can get VERY loud at night, so be prepared for that) and there was a nice breeze.
For me, it was fine. I'm glad I stayed there and it all worked out (and I will say that that host was very apologetic about the check-in issues and allowed me to check out a bit late, so I can chalk it up to a genuine human error). I'm not sure I'd stay there again, but if you're looking to be in the Marais district and have an authentic Parisian loft experience, you'll be fine here.