Issa was very welcoming, great communications and even met us off the train at Gare du Nord which made everything very easy. He also gave us a really useful set of local maps and suggestions for shopping and eating. The apartment was small but had everything you could want in the way of equipment and facilities. Really conveniently located for various metro and RER trains as well as Eurostar. As a result it was a little noisy with trains until around midnight, and again from around 6am, but quiet in between.
The boulangerie/patisserie on the roundabout was absolutely lovely, with really friendly patient staff, the veggie Sri Lankan restaurant was also tasty and really good value and the Leader Price store was surprisingly well stocked for groceries and open until late (except Sunday).
The twin beds for the children were comfy and they loved that there were children's books in French and a few toys left for them. The sofa bed was not quite so comfy, but fine for a few nights. If we were staying again we would probably take the option Issa offered of sleeping in the twin beds and putting little mattresses on the floor for the boys.
We like to walk from place to place when we can and it was easy to walk to the Pompidou Centre, Notre Dame and the Sacre-Coeur. It's also really close to Canal St Martin which is a lovely place to walk/run/skate.
We would be happy to stay here again next time we are in Paris, and it will be my first place to check for availability. All round a great option for travelling with younger kids.