Very cosy. Suitable for a long stay because you can have your own space (bedroom) which is pretty comfortable size. Great location like it is claimed. You can walk to Banhhof (both SBahn/UBahn) in 3 mins, or maybe 2 if you run, and the bus stop is even closer! If you're looking for a peaceful place to stay, I recommend you his place. Although there's no hip cafe and mostly you see only old people walking around the neighbourhood, you still can take a bus or bahn to Boxhagener Strasse or Warschauer Strasse or Alexanderplatz in, like, 15 mins.
Cleanliness is not perfect because it is an old building and is a real house that he's living in, not like a newly renovated apartment for hostel business. I had been staying in the period of a kitchen and a bathroom floor renovation, so a bit dusty on the floor but it didn't bother me that much as long as I brought my indoor sandal with me.
Adan is a sincere host. I myself am not a fan of a small talk actually. Still, I hadn't feel uncomfortable at any time when he's home. He gives me my own space and didn't try to approach me too much, like a good parent haha. Also he can recommend places and events.