This apartment was absolutely perfect for us in exploring all parts of Paris - all you could want for a stay: safe, quiet, well kitted out, in a great neighborhood, with an outstanding host.
We stayed for 6 nights and simply walked over from the Gare du Nord; the location is ideal for walking to all parts of Paris, and also for catching the train (from St Lazare) to Giverny and Versailles.
There's a great supermarket just down the road, plus a boulangerie, and the restaurants opposite are great if you want something close to home.
We couldn't recommend the apartment or Vincent more!