We had a pleasure to be hosted by Gerhard during our first trip to Berlin!
This place is highly recommended for couples who appreciate a quite, cozy and homelike flat, which is accessible to major kinds of transportation (we've also biked and walked a lot!). The flat is located in a very nice neighborhood, surrounded by supermarkets, neat restaurants and cafes and a unique wine bar right at the corner.
Moreover, Gerhard's tips and daily concern made our 7 day stay just awesome! =)