We stayed for 2 nights. You are definitely paying a premium for the location, which is amazing. This was my third visit to Paris and the best location I've stayed in! You are just 2 minutes from Place St. Michel and the Latin Quarter, 10-15 minutes from the Marais, 3 minute to the Cluny Museum, etc.
The front desk staff was very helpful and friendly (a first for me with Paris hotels!). Car service to the airport was booked through them for only 60 euros.
The rooftop lounge is great! Get up there at nightfall and watch the Eiffel Tower sparkle :)
Our room was a decent size for a European room (we were upgraded to an executive room) and had air conditioning (that worked really well). Bathroom was a good size and had a rain shower/bathtub combo. Bathroom amenities were provided (shampoo, conditioner, lotion).
Bed was soft and pillows were lumpy.
The reason I am giving it 4 stars is because of the internet. Internet connection for regular surfing was great; however, we were unable to Skype, Facetime, or use Magic Jack for calls. If you waited until midnight then it would work.
Delicious boulangerie about 5 minutes away. Ask the front desk for directions!