I stayed three months at Matthias and Michele's during my internship at Berlin. The location is very convenient for access to public transportation and the neighborhood is calm. Viktoria Park is just a few steps away and is a very enjoyable place to walk and stay after a busy day. Supermarkets are also just a few minutes walk which is very useful. And if you want some restaurants you'll have only 10 minutes to walk to Mehringdamm. Just be prepared for some daily exercice because it's a fourth floor appartement without any lift.