This apartment is in a fantastic location. You can walk to many of the main tourist sites such as Centre Pompidou and Notre Dame. There are also some first class museums in this quartier. I recommend the Picasso, the Carnavalet and the Arts et Métiers museums, all very nearby. The Marais is a lovely area to explore and we ate out at local restaurants every night.
The kids loved the quirky sleeping platforms in the bedrooms. The place is not huge but having lived in Paris I knew that would be the case. Despite its central location it was lovely and quiet at night.