I am just home (NYC) from a week in Nicolas' terrific loft space. I concur with other guests' comments: location is perfect for getting all over the city as transport to/from Gare de l'Est is easy (try the bus system); the space is clean, extremely comfortable and the kitchen is both equipped and easy to use. Do explore the streets off of rue Paradis - a bit of old Paris at its best. Above all: Nicolas is the ideal host: attentive, very responsive and his place is exactly as he describes it.
A little tip: the city bus #350 offers regular service from the Gare de l'Est to CDG airport and costs only €4.23 (3 metro tickets), a short walk from the loft and no metro crowds and stairs to contend with! Same advice for arrival.