The walls were a bit thin and one night could hear the neighbors showering and the wifi really stopped working every night at about 10 pm.
Otherwise, as others commented, the breakfast was expensive for what it was (coffee, tea, cheeses, baked goods, juice, toast) but for us it was convenient not to have to find a place to eat first thing in the morning while it was 2 degrees out.
The bed was super comfortable, the room was warm and cozy (not too small, like some commented. Just right for us), the location was great for being able to walk to the Eiffel tower and Champs Elysees, and the staff were very friendly and helpful. I loved that we were located right over a pedestrian road with a local patisserie, boulangerie, fromagerie, and several restaurants.