The location was amazing and so close to the Luxembourg Garden, the Latin Quarter and the best of St. Germain was great. Then we walked to all the attractions that we wanted (@1 mile to Louvre, @2.5 to Eiffel tower via the Seine and @2.5 to Sacré-Cœur Basilicaand Montmartre). Of course the Metro would make them even quicker. You can just stop and grab a delicious meal at any of the cafes in that location! You do need to be prepared for stairs, as advertised, but that gave us the best views.
The deck is amazing and being able to see the Eiffel Tower light up on the hour for the holiday season was an added bonus. The kitchen had just what anyone would need, including tons of glasses, plates, bowls, a coffee maker and a dishwaser! Laundry there if necessary (dryer is pretty standard of Europe in that hanging them is faster)... Also, cannot recommend a running tour enough. https://www.tripadvisor.com/Attraction_Review-g187147-d1815347-Reviews-Paris_Running_Tours-Paris_Ile_de_France.html
Overall, a just perfect and beautiful place to see the best of Paris. Cannot recommend it enough.