It’ s a very nice styled and light appartment in a lively area. I stayed for 6 weeks. All you need is there, and Karl is very helpful to solve issues. Like Ali of the tapasbar next door.
The appartment is in walking distance from Gare du Nord, and the Sacre Coeur. The metro is close by, but also the velib bicycle or dott steps.
The area is colourful and lively, what makes it interesting and a interesting mix of cultures, shops and restaurants.
Take your earplugs with you, otherwise cafes and street cleaning services can keep you awake.