We spent 4 nights here and it worked out perfectly! Location is great: short walk to several Metro stops, easily accessible by taxi or Uber and great views at the end of the street in either direction. The apartment is as described: small, cozy, nicely appointed and perfect for 2 people. The check in and out process with the manager Dante was great. He walks you through everything and makes sure you understand and can do it. We felt safe and followed the instructions for the shutters and the door lock.
This is city living and when there is noise in the street, you hear it, so if you are not used to city noise, you may want ear plugs to sleep (it was not all the time, garbage day mostly). It was nice to have a small kitchen to make breakfast. Kitchen is sufficiently stocked with pans/dishes/ etc. and all kitchen appliances worked well (we did not use the laundry machine).
The bed was comfortable, as others have mentioned. My over 6 foot tall husband had to watch his head in part of the bathroom, but that was easy enough. The heat was more than sufficient for the apartment and it had units on both floors.
Dante also gave suggestions on market, restaurants and boulangerie and they were all good.
We would definitely stay there again after having such good experience at Nishu's!