So first the positives: Location is very convenient (between Arc de Triomph and Tetuan metro), terrace is gorgeous with great views, and the couch is probably the most comfortable thing I've ever sit down on. Laundry in-room was a big help to us also as we were on an extended trip and needed it badly!
Negatives: As other reviews have mentioned, water pressure lacks a bit in the shower. Wasn't an issue for me, but wife said washing her hair was difficult. Also, if you are particular about bed comfort, be advised: it is a bit uncomfortable. It feels as though there are a lot of springs poking up and there doesn't seem to be a mattress topper to help (as of 7 Nov 2018). Please confirm your check-in time a day before if possible, as ours got mixed up and we ended up waiting another hour and a half.
Overall I would give this a B/B-. It was more that there were just a handful of small things that took away from the apartment, but overall it was ok to stay in for a few days, which is what we needed.