Warm water was intermittent sometimes. We would need to open the hot tap and then wait for 5-10 minutes until the warm water finally came. Even after that, the temperature of the water would sometimes temporarily change, which could produce some interesting reactions while under the shower! ;)
The internet, while perfectly serviceable for light Web browsing and occasional Skype call was somewhat intermittent and slow at times. You need a separate username/password for each device and after a few days, one of our devices stopped working even though the other devices still connected fine... fortunately, the staff was super helpful and quickly provided a new username/password.
Breakfast, while generally delicious, was a little too simple for the price (15 EUR) and the Swedish table was not always fully stocked - omlet, croissants, milk and other food items were occasionally missing.
Wonderful, welcoming atmosphere.
The staff was very pleasant and helpful. For example, when we needed an ironing board, they simply brought it right into the room!
Good sound isolation. Peace and quiet, combined with lush bed lead to a very good sleeping experience.
The space in our room (Superior Double Room, 5th floor) was ample by Paris standards and it was generally very clean and comfortable.
The bathroom was warm and clean and the toiletries were of good quality.