My boyfriend and I stayed in Andreas' apartment in Berlin on holidays, and had a great stay!
In terms of location it is perfectly situated in the trendy Prenzlauer Berg district, right outside a tram stop. We found it easy to get to all sights and plenty of cool cafes, bars and restaurants are nearby.
The apartment itself (staircase only) is spacious, comfortable and quiet, with a bachelor pad feel, although it could be more thoroughly cleaned. Andreas was a great host who efficiently organised check-in and ensured we were comfortable during our stay. We would be happy to stay there again!