Pros: (a) Great location; right next to Gare du Nord. (b) Excellent communication; Didier is constantly keeping tabs on anything you might need. (c) Clean place. (d) Good wifi. (e) Good water temperature in the shower. (f) Breakfast included plus some food in the fridge and coffee at your disposal (my girlfriend loved having coffee every morning). (g) Washing machine included; Didier even provides the detergent (this was a life-saver for us as we had been traveling over a week across Europe by the time we got to Paris).
Cons: With a place and host like that there are NO cons at all.
In summary: I would totally recommend this place to anyone visiting Paris. We will definitively consider going back to Didier’s place when we travel to Paris.