We had 3 adults at Romain's apartment for 5 nights. He met us for an orientation (dishwasher, TV, washing machine, wifi, local food/shopping/metro) before heading out. What you get is a highly functional apartment in a great location. I was extremely happy with the value we got for our money.
The bedroom is in the interior, well protected from any street noise and very quiet and comfortable. It was bigger than the pictures show and has an interior balcony with table and chairs. The other bed is a fold-out sleeper sofa in the living room, which worked great. Paris is lively at night, so earplugs are a good choice to ensure a solid night's sleep, which worked great for us.
We preferred breakfast in the main space with the windows open, letting in the air, sun and sounds of Paris.
Location is excellent, 1 block from the metro, 15 minute walk from Notre Dame and the Louvre. My favorite was walking 3 blocks to Rue Montorgueil and shopping for breakfast at the boulangeries, patisseries, fromageries, boutcheries. 2-3 in each category, plus numerous brasseries. We had a fabulous Parisian dinner there as well (about 100 euros for 2 of us including drinks).
The living room was very comfortable for relaxing after a long day of sightseeing, the kitchen efficient enough to cook some meals if you desire (3 burners and an oven) and the shower is roomy and likely one of the best you'll find in an apartment.
Security is good, as you have 2 locked doors before the single flight of stairs (standard, narrow Parisian stairs, so take this into account) and then a very secure door to the apartment.
Overall, I'd recommend this rental for the location, great communication from the host and amenities, all of which seemed extremely good for the price.
Thanks, Romain. We had a great time.