Julian's place looks as advertised. It is a very nice, cozy room, full of plants with great light and stylish. The bed is comfortable, the sofas too and the table is great for working. The bathroom and the room were clean and the kitchen was well equipped, although I didn't use it.
The apartment is well located in Neuköln, very close to many public transport alternatives, cool cafes, bars and restaurants. From there it's a 25-30 minute ride to Mitte.
I had a good communication with Julian, he was very responsive and I would stay at his place again.