This listing is amazing. Great, modern, clean apartment. Looks exactly like the photos: spacious, on the top floor of a 5 story building so some good views too. There are some great places to eat at your doorstep (literally) and about a 5 minute walk from a train station sir decent links to central Berlin.
I couldn't have asked for a better place to stay.
Although I didn't meet Sebastian he was a great host as he kept me informed and was very helpful - as was his housemate.
Thanks guys!!