I did not meet Charlotte personally, but she was very responsive via email. She was very accommodating with the check-in and check-out times. Her husband, who owns a beer store right across the street gave us the keys, and was super helpful with the luggage.
The apartment is well appointed and comfortable, it can easily fit 4 people; we were only 2. The mattress on the bed is very firm, which exactly how I like it. The water pressure on the shower was surprisingly strong.
The wooden floor, like in older apartments, is creaky, but this did not disturb us at all. The apartment itself faces a courtyard and is very bright and quiet. The neighbors seem to be particularly wary of noisy people - I was immediately warned by the next door neighbor not to shut the door loudly after hours...
Wifi and internet worked perfectly.
The location is absolutely superb - right in the Marais, but also very close to the Bastille area and the lively 11th arrondisement. There is an enormous quantity of wonderful bakeries, restaurants, bistrots within walking distance, and on Sundays it's right next door to the well know Richard Lenoir street market.
All in all, a fantastic stay, and I look forward to booking it again in future visits.