Tranquil, clean, well-appointed apartment in a bustling, multicultural but safe, area of Montmartre. Kettle, toaster, coffee machine, plenty of hot water on demand for showers and baths, and even the sofa bed is comfortable.
At night, sitting on the living room terrace with a beer, you can see the searchlights from the distant Eiffel Tower sweeping across the sky.
Metro Line 12 (station Marcadet Poissoniers) is two minutes walk, Line 4 (same station) a little further. It was easy to get into the centre of Paris. Get yourself a Metro map (or the RATP mobile app if you have a SmartPhone and it's fairly easy to work out routes.) Wifi is fast and reliable, and Valerie also invites you to use a guest account on her own computer should you so wish. Valerie was there to meet us, explained how things worked (nothing difficult) and left us coffee capsules for her Nespresso machine which were most gratefully received. We returned late each evening and found the streets busy even at that time, so no worries about the neighbourhood. It was so sad to see a couple of homeless people sleeping in doorways on a nearby street, but we saw evidence of that everywhere we went. Homelessness is a problem in Paris at the moment, made worse by the economic crisis. Having said that, it's probably not much worse than London.
If you are returning to Gare Du Nord with heavy bags, recommend you get the 302 bus (turn left as you exit the apartment, immediately right, and it's 200 yards up the street, opposite the supermarket and just before you turn the corner for the Line 12 metro entrance). It's a 15 minute bus ride and no steps to deal with!
In short, Paris is beautiful and Valerie's apartment will be a home from home.

P.S Nothing at all to do with Valerie or her area, but it's wise to avoid the myriad conmen or illegal street sellers around the TOURIST areas, especially the steps of Sacre Coeur. If someone approaches you trying to sell or even claiming to GIVE you something, walk on and ignore them. They can be quite persistant and we saw a few tourists caught in their trap. Be assured Valerie's apartment is in a local residential area and is completely free from that sort of thing.