Frank's place is extremely clean and well maintained. However, we were not warned that there was painting work going on in his building and that made getting in a bit of a mess. But it's just temporary so I guess that's okay.
It is very well located and really close to the metro station as well as a really. Nice mall to get daily supplies and other shopping.
His street has an excellent Greek restaurant walking distance and other salad, fast food and shops nearby.
Overall a good experience and easy to get around Berlin from his place.
The house is quite sparsely furnished and a little expensive for that but the location makes it worthwhile!