The apartment is very cozy. It's very nice and clean on the inside with excellent facilities including a fridge, stove, kettle, microwave, spices (for cooking), towels, hair products, hair dryer, washer, etc. It has an air-conditioning unit that does the job although, for best operation, needs the assist of an electric fan for air circulation; fortunately Sebastian provides a decent one. The stairs inside, especially up to the loft where the bed is, are smaller than we are used to. Manageable if you are stable on your feet but these could be problematic for those with walking issues.
Finding the building was easy but finding the entrance to the apartment was a bit difficult; however, Sebastien's directions and his video introduction are accurate; trust those and you'll be fine. Opening the front door can be a little awkward as the restaurant in the same building props their kitchen door open from time to time. It's manageable especially once you have your luggage inside and are just going out on the town.
The location is excellent with quick access (less than 5 minutes walk) from at least two different Metro stations.