My wife and I stayed here for our first trip to Paris and we weren't disappointed. A stones throw from a Metro station (Pernety or Plaisance), the Atelier reception staff had a welcome smile and offer of a drink to wash off the travel dust.
The hotel room was just as advertised on the website, complete with funky bathtub (we stayed in the Havana club), double aspect windows and super comfortable bed. Our only minor, and it would be the only criticism given the sizes of French hotel rooms, would be the toilet is about four foot from the edge of the bed, separated by a sliding door. That's it, not much else, perhaps a large mirror for the vanity table.
Breakfast was superb, the staff always on hand to re-fill or assist should you need, setting us up for the day; after a busy day of wandering the Parisian attractions, return to find the room refreshed; fresh towels daily and fresh sheets after two nights, excellent care for our belongings (I'm a bit messy) and overall, everything you expect from a hotel with a huge dose of personal care. A short walk nearby, search out the secret little Bistrots and stay off the main road for real French cuisine.
Our tip, if you can stretch to it, go for the Havana club as its fantastic value for money, we would rate this hotel above three star.