Perfect location near the place our daughter was living, so a great spot for our visit. Also SO close to the S Bahn, bus, and to any shopping needs, etc.
It is a walk-up, which was absolutely fine for us but if 80 or so steps would be problem that is something to note.
Great communication from host and easy check in and out.
Stay in a place like this if you want to feel you are "living in" Berlin, not just "touring." Nice.