It is a very basic place,if you are arriving and departuring from Gare du nord it is a very convenient place to stay since it is just a 10 min walk from the station,i stayed there with my 9 year old daughter and i had no problems whatsover,when it comes to comfort i cannot say it was good. Beds ok but not comfortable. Many dodgy looking people in the area selling cigarettes near and around the square but nobody bothered us.downstairs on the way to the rooms they have a fridge,microwave and a kettle for guests to use which was a bonus.you can bring your drinks,cheese etc and store there to consume when you come back from a day exploring Paris.
There is a Metro station 2 minute walk from the place which makes things really easy.
For the price i would stay here again if i am arriving at gare du nord. You can also walk from there to the sacre couer.
If you need a place to crash for a few days and they are not charging a lot a the time of the booking it is worth staying there,if they are charging more than 60 euros i would stay somewhere else