The studio is a nice place, more spacious than it looks in the pictures, with tall walls and a big window. The bed is a sofa-bed for two people, just okay for a couple of nights, the comforters and pillows make it very comfy. There is also a sink, a microwave and a minifridge in a separate room. The restroom is not very big, but two people don't need more. Everything was alright, Zito and Zohra were very welcoming, and flexible when we needed to meet with them.
The only thing we struggled with was that there's no wifi, but we knew that already. We did need to take the tube/train everyday to get to the center, because Berlin is such a wide city. If you're staying 5-7 days I recommend to get a 7 day ticket (there's only one kind of ticket for all public transport).