We throughly enjoyed our stay. Perfect location, especially for art lovers, literally steps from both the Louvre and the Orsay. Several good restaurants on the block or around the corner. Friendly people at all the shops (bakery, cheese shop, butcher, pharmacy, etc). Also very close to all the great St. Germain shopping.
The apartment itself is comfortable and spacious. It's nice having the split level for privacy when traveling as a family. Our kids liked having their own downstairs bedroom, though it does get quite a bit of street noise as its right over the street. The upstairs master bedroom is very quiet.