We stayed at Laurent and Lisa's place for 3 nights only.
The accommodation is about 20 min walk from Gare du Nord and easy to find. Unlike most places we looked at during our search, it's quite spacious with a big wardrobe where you have plenty of space.
There are plenty of restaurants and vine bars nearby as well as a supermarket just next door which is open 7 days a week (and even open on May 1st).
There is a nice boulangerie/patisserie (Les Gourmandises de Saint Lazare) just 5 min walk down the road - much cheaper than most others we've been to, very friendly staff - unfortunately only open Mon-Fri.
It was great that we were able to check in early on our day of arrival, so we didn't had to store our bags in the lockers at Gare du Nord.