The apartment in Rue Mouffetard was perfect for our family of four (two teenage boys!) when we stayed in Paris.
The location is excellent - could not fault it.
We were about 150m from the Metro and the street has all the food and drink you could need in Paris.
We did not cook any dinners while at the apartment because we chose to enjoy all the Parisian food, so we cannot comment on how the kitchen works, but otherwise the apartment is very big for Paris and is easy to enjoy as a family.
It has a living room, three distinct bedrooms - a double bed and two singles - and even two showers! (While one is very small, it works just fine)
For location alone, we would recommend Claudio's place.
Claudia was lovely and easy to contact.