The room is tiny. But lovely. It offers an unbeatable location, close to many restaurants (especially asian/japanese) and a mini supermarket with everything, literally round the corner, at Rue du 4 Septembre and Rue de Gramont. The 2 Metro stations (Opera and Quatre Septembre) are literally 2 mins away and there is a direct connection to Gare de L'Est (M7).
Because of the size of the room, if you travel with big luggage you might have issues with the space available (there is a lift to access the apartment at the second floor though).
If you plan to stay more than a couple of days, bring/buy some shampoo/soap. The ones provided are of a very small quantity.
Wifi is very usable (10Mbps). The TV has no streaming services (it is not a Smart TV), so if you really want to stay in the room to stream content, bring your own streaming device (you might be able to plug it in).
Because of the very central location, you can walk most places (e.g. Louvre), but beware that at night the road can get noisy (i.e. traffic, honking, garbage collection, deliveries) - bring earplugs or keep the window closed. A small fan is provided that provides relief during hot days.
Elodie and her friend Isabelle, taking care of check in, are helpful and responsive making the overall experience very positive.
I will seriously reconsider this location if I return to Paris. Even with the (understandable, considering the location) limitations above (i.e. occasional road noise at night, size), I highly recommend it!