Arnd and his place were one of a kind.
Me and my girlfriend loved Berlin most because of Arnd. Very polite, clear and incredible helpful (he proactively gave us directions to reach another airport when we were leaving). Not to mention teas and coffee free to serve.
His place was almost ours. 100% privacy with a great and warm bedroom and a great bathroom. Bus stop in front of his apartment and Metro lines a few minutes walking. It was very easy to know the city by walking, all of sudden we met Brandeburg Gate - and we were just starting to walk!
Totally recommend Arnd and his place. ;)