We only stayed for one night, but definitely would stay for longer if we had the chance. The place was perfect for 2 couples, the beds are quite private from each other, the beds were comfy, the 2 bathrooms were handy, the AC was nice, and the gallery environment was a cool alternative to a typical airbnb. Never got to try out the bathtub, next time!
The location was great because it's really central, between a lot of different neighbourhoods. Close to some major touristy sites, and also the Kreuzberg neighbourhood. Berlin is great city for biking, or scootering around. Would come back for sure!