We had a very good time. The communication with Karsten was very pleasant and easy-going. The apartment is exactly like it shows on the pictures, even though it seamed even bigger in real life. Everything was clean and complete. Good bed and shower, too.
The only thing that was a bit disappointing to us was the neighbourhood. In order to be in nice places you either had to walk a lot or take the tram.
But apart from that we can surely recommend it.