Mathieu is a very friendly, patient, and conscientious host. Out of the nearly dozen or so Airbnb's we've stayed at around the world, I think Mathieu would rank #1 in hospitality. Combined with his the amazing apartment, I would highly recommend a stay a Mathieu's to nearly anyone.
With respect to Mathieu, in addition to providing us with directions and offering to meet us at the nearest metro, he gave us a tour of the apartment, answered all of our questions, and gave us some tips on the surrounding area. He left a few items for us such as coffee and pain-au-chocolate which we gladly ate and drank throughout our 5 day stay, as well as shampoo, body wash, laundry detergent for the washer/dryer, and a host of other small items. All of this, I thought, was quite generous and very thoughtful. He also provided us with multiple methods to contact him should we have questions or need help, and was extremely prompt when responding to enquires.
His apartment is cozy and well-organized, offering lots of open space and areas for luggage. It is also well furnished and contains all the amenities of home, including a full kitchen set, dish washer and and a combination washer/dryer. The sole exception to the list of amenities of is an air conditioner, which didn't seem too necessary given given Paris' cool temperatures and the fact that Mathieu's apartment has large windows which, when open, catch strong drafts. In terms of look and feel, Mathieu's apartment looks nearly identical to the photos posted on the listing.
Mathieu's apartment is located in a very convenient area which, while not necessarily "downtown", is accessible to at least 3 different metro stops within a 5 minute walk, and is a (really scenic) 40 minute walk to the Notre-Dame.