Excellent location between Ringbahn and Alexanderplatz, tram stop a block away, countless restaurants and a Rewe supermarket right outside the door. Parking is €1/hour and tricky to find, would recommend public transport.
Walkable, safe area, quiet yet centrally located. Excellent communication from host.
As others have mentioned, if you have knee issues or are seriously out of shape the 84 steps up to the apartment will be a challenge.