Robert is one of those people you meet in your life where you feel lucky to have crossed paths with. A kind, thoughtful, caring and generous person which translates well into an outstanding host. His apartment is located an amazing neighborhood with lots of great little shops, delicious places to eat, cool museums nearby (Ramones Museum), and very convenient for public transit. I was out late for a night and felt very safe in the neighborhood as well, if that is something you want to explore while in Berlin.
The bed is comfortable and the space is very homey. Robert took me to a yoga class the morning after I arrived where he goes to frequently, just down the street. It was an amazing class and just what the doctor ordered after 15+ hours of travel! It's free but after class they tranisition the space into a coffee shop so make sure you grab a cappuccino :) I visited Berlin by myself without knowing anyone, but I left with a happy heart and new friends. It wouldn't have been the same without Robert! 10 out of 10 recommend staying with him.