I went to Berlín with my boyfriend for a 4 days trip and Günter's flat couldn't be better: perfect location (Kreuzberg is beyond beautiful and a livingly hood), all the needs you could ask for and so cozy.
The subway is just 3' walking and you also have reting bikes near by.
In addition, there are pharmacies, stores, supermarkets and very good restaurants just a few meters away.
The communication with Günter was really easy, he is so kind.
I have nothing but good words for this appartment, looking forward to come back to Berlin, would surely repeat :))