Person who met us was helpful in terms of explaining the apartment. A little better directions before hand for how to get from the Les Halles train station to the flat would have been helpful (in our jet lagged fog, we wondered for 30-45 minutes in what turned out should have been a 5 minute walk).
Space was adequate for our stay (2 adults plus teenager); I think it would accommodate a family of 4 readily, but more than that would be tight (especially with a single toilet)
Location is great! Flat is very quiet, even though it is in "jumping" neighborhood - it is very light and airy feeling.
Our major complaint is if the apartment were jsut slightly better equipped, it would have been even better - e.g.,it would be nice to have a couple of bars of soap in the bathrooms upon our arrival; more than a single dish towel would have been useful; coming from the States, as adaptor for the outlets would have been appreciated; some hooks to hang towels in the second bathroom would be nice, rather than having to leave towels on the floor.