I had the pleasure of staying at Claus's apartment with my partner and young child. We had previously stayed at another AirBnB in the same area. It was nice, but this apartment kills it. It is exactly as described - modern, very spacious, delightfully crafted. The view is great. The neighbourhood is great ( go to the Pony Saloon just up the road, best bar I've been to in Berlin). His music and books are great. We didn't meet Claus, but in spite of our very late arrival there were no problems with access. If we were going to buy a place in Berlin, we would pretty much want it to be just like Claus's place. If you are looking at renting, you will not do better. We will stay again if he lets us.