Björn is a fantastic host: he helped me in every possible way during my 2 weeks stay.
The apartment is gorgeous, much nicer than the pictures. It's super clean, new and perfectly equipped (kitchen, bathroom, plenty of towels, bed linens, even equipment for small babies). It's just few steps from the subway; the neighbourood and Kastanienallee are very lively with lots of restaurants and shops, but the apartment faces one courtyard and a garden and what you can hear are only singing birds! It's on the first floor (easy to reach with the luggage) but full of light and sun! I think it's not easy to find nicer apartments or hosts: highly recommended!