Spent a week in Paris with my wife and another couple, and we all thought this apartment was outstanding. Biggest plus was the location, which is right in the heart of St. Germain. We quickly established 'our' local shops, including bakery, wine shop, grocery, outdoor market, and many cafe/bistros. You'll love the convenience of having access to everything literally a few steps away after a long day of sightseeing.
The apartment is as advertised, which is to say it is very modern, bright, clean, and has plenty of amenities. Just as a heads up, the second bedroom is very small, with a fold out couch, but it's quite and has plenty of privacy (including attached bathroom). There was no complaints from our party on the setup.
Johan is very easy to work with, and his partner David does a great job showing you around the apartment and is always available (thanks again to David for the quick visit to help out with the wireless internet...).
Highly recommend this apartment if you are staying in this area of Paris. And if you are unsure of which neighborhood, I'd also recommend St. Germain. We hope to make a trip back again....