We stayed at Matthias' place for four days during New Year. The experience was even better than we expected:
Matthias is a very communicative and friendly host that gave us clear instructions about the apartment. It is situated in the south of Neuköln, the apartment is very light and sunny and the interior is very welcoming. Also we liked the overall quality of acoustics: well equipped sound stereos and a nice vinyl collection!
There are 5 sleeping rooms with double beds and the kitchen is very inviting to cook all together.
We'll come back for sure!