We had a great time staying at Antoine's flat. A friendly friend of his met us at the flat and welcomed us with a tour of the features of the flat. It's a well-decorated place that makes you feel right at home, and Antoine's collected furniture and artifacts from all over the world from his personal journeys. His cacti collection is great!

The flat is on the 4th floor, but the building does have a lift (which I understand is a rarity in Paris buildings).

The neighbourhood is a brief walk (~15 minutes) from Gare du Nord, and within 30 minute walk to the Louvre, Notre Dame, etc. There are plenty of good restaurants nearby, in particular: http://www.yelp.ca/biz/la-petite-rose-des-sables-paris

The flat is in a building on a main street, so be aware that it can be a bit noisy if you need the windows to be open at night.

We had a great time, and would definitely recommend staying in Antoine's flat again!