Franz's place is THE BOMB. Seriously well located in a good street with lots of cool bars, cafes and restaurants within walking distance, as well as nature (a big park on one side, river walk on the other). We loved it. The bed is comfy and the place is really beautifully and thoughtfully designed. The bonus is that it's a converted street front, so when my girlfriend and I hosted friends over one night, we opened the big windows facing the street, took some chairs out on the street and it felt like we were sitting in the coolest Berlin pub - our own!
Lastly... I forgot 2 items when checking out - a pain in the ass for any host - and even though Franz was out of town he organized for me to pick them up in the next few days. 10/10 AirBnB experience here, would definitely go back. Thanks Franz!