Birgit is a welcoming host and made me feel welcome. She has done lots of interesting things in life and is great to chat to. The room is spacious and comfy. I would definitely recommend staying. The flat is at the top of the building so has great views but lots of steps up, so not suitable for anyone with mobility issues. The bed is very comfy, I slept well. If you are a light sleeper then take some earplugs though as you can hear the trains a little. Great accommodation, great host, and very central nice location in Berlin.