The host, Daniel, Nora's flatmate, was very welcoming and responded quickly to my messages. Arranging to pick up the key was easy. The room is very big, the bed very comfy and thanks to the windows you do not hear the busy street outside. So, definitely a good experience, I would recommend this stay to couples and single travellers.
The neighbourhood Neukölln has improved over the years, it's still a bit shabby but nowhere as creepy as it used to be.