Stefan's apartment was perfectly located for taking in Berlin. It's very close to a lot of transportation and many things are walking distance from the front door.
The apartment was VERY clean and very comfortable. The one warning I would give to anyone looking at this place is that the park can get a bit noisy on the weekends. BUT the balcony and the park are one of the best things about the apartment so it's a trade-off. We are city people so we didn't have a hard time falling asleep but I think it's a good to be aware of.
Great neighborhood. I would consider staying here again when I come to Berlin for sure.