The studio of Pierre et Katia is something special!
If you look for a quiet place in one of the coolest arrondissements in Paris (11e), you should definitely go for this one. The design of the flat is clever, the bed is cozy and the bathroom quite nice.
Please be aware that the stairs to the first floor are quite narrow. Some people tend to ignore the fact, even though it is indicated in the description.
The whole check in works with an concierge company, which was no negative point for us at all. Despite that fact the communication with Pierre was flawless and friendly.
We had a small inicdent, when i wanted to take a shower. After a few minutes the whole bathroom and even the entrance very flooded, because the drain of the shower wasn't clean. This was more the fault of the cleaning company, than Pierre's fault, so we don't blame him at all for that. He reacted very quickly and already contacted a plumber. Just be aware to check it, if you want to relax under the very cozy shower.
My girlfriend and i spent some very nice days in Pierre and Katias Studio, which somehow is very parisian (not the Emily in Paris one though :D)