Stayed three nights in this apartment. It is in a great location and, as long as you enjoy walking, you can walk to most of the sites. We walked about 25,000 steps a day and visited Sacré-Cœur , Louvre, Eiffel Tower, Trocadéro , Notre Dame and more. Lovely walks along the Seine and convenient for some great shopping. There are also several Metro stops within 5 minutes walk of the apartment.
Apartment was clean (but in need of a few small maintenance jobs), very light and warm (we stayed in Feb).
Unfortunately we were a little unlucky in that there were parties in the building on 2 of the 3 nights we were there. The party immediately below us on the first night did keep us awake.
The apartment is on the 5th floor. There is an elevator (very small!). The stairs are not particularly well maintained (carpet was loose in at least one place) and one window was smashed overnight after the first party.
Bottom line is we would consider staying their again, perhaps mid week.