We had a great time at Frank's apartment which is located centrally and close to public transportation (U-Bahn, Straßenbahn, Bus). You can hear the tram passing by from time to time but that didn't really bother us nor interrupt our sleep. There is also a nice park as well as a supermarket and little cafés/restaurants nearby. Communication has been easy and Frank has been quick and responsive. All in all, we really enjoyed our stay and would come back.