Having stayed here for three nights I'd highly recommend this apartment. It has everything you'd need for a short visit - although we only really used it for sleeping!
It's location is great - 10 minutes walk from Gare du Nord and 5 minutes from the Chateau Rouge metro station. Perfect for exploring Montmartre, Paris and beyond.
Jean is an ideal host - easy to communicate with via email or text. The only shame is that we didn't meet him; our flight arrived late so we picked up the keys at the bar at the end of the road.
If we're back in Paris we would definitely stay here again.