The place is perfect. It's close to the Seine, yet still very much in the Marais. We had a lovely duplex room which was stylishly appointed. In fact, the entire hotel had a distinctly charming and stylish feel. The lady at the reception was incredibly friendly and helpful in getting us a taxi on a day the public transport was striking.
The continental breakfast was a bit basic for my taste. That's pretty much the only quibble. I'd definitely consider it again.