We stayed just for one night at Guillaume's apartment with our two young children. We had a great time and the place was perfect. Check in process was easy, Guillaume was very helpful and ensured we had no problems. Very secure parking space deep in the basement below the building. The apartment was fantastic - it is very tastefully decorated. Very stylish. Well equipped. Excellent location right in the heart of Paris. A short walk to Arc de Triomphe / Eiffel Tower / Champs Elysee.
The listing advises may not be suitable for young children. We would agree as there is lots of delicate / nice furniture in a compact space. Okay for us as we were not there for very long but a toddler could cause serious damage if unattended!