Johannes is great, really friendly, helpful and went all the way to make sure we had absolutely everything we needed. He lived next door but wasn't the least bit intrusive. The location is super great for getting around Berlin, in a really cool area with a U station and the shopping centre around the corner, great food options and the airfield really close. The apartment is really cool, while quite "raw" it has everything you need, with loads of space and a very nice and relaxed vibe. We really enjoyed our stay. We were very pleasantly surprised upon arrival and it looked much nicer than in the pictures :D