We traveled to Paris with our young kids. We wanted a place that wasn't in a touristy area and this definitely made the cut. It is very small but well laid out and well made to fit everything you need in a small space. It comes with all the necessary amenities for medium to longer stays and even includes as washer and dryer. Greg accomadatee our schedule change when we first arrived and was there to meet us immediately when we arrived making it a smooth check in.
This is an aside but I will say if you have younger children, be sure they are the type that will not try to climb up to the loft bed. It is pretty high up and not safe for young kids. He warned us when we got there and our kids listened to our warning.
But if you have young kids who won't listen, I would possibly consider somewhere without this set up.
All I need all it was a great trip made comfortable by this apartment.
Oh and it is close to two different stops on metro (line 13), many busses and a 30 or less minute walk to montparnasse.