We had a lovely stay at Oliver's house. We did not have the chance to meet each other but Oliver was really helpful, gave us many tips and arrange with a friend to give us the keys.
The apartment is bright, big and with a nice zen buddhist atmosphere. The kitchen's shelves are made for tall people ;) .
The apartment is well located in a quiet neighbourhood, a 5 minutes walk from the S-bahn station Julius Leber Brücke that has a lift which we appreciated as we were travelling with heavy luggage and a baby in a stroller. We left the stroller at the entrance of the building but had to climb to the 4th floor with the luggage...that was hard!
There is an Edeka supermarket and a Bio market close to the S-bahn and a nice playground really close to the apartment.
We highly recommend a stay at Oliver's!