The apartment is located in a central zone but also quiet. It is at 17th floor so you'll have a pretty nice view. The interior of the apartment is clean with many instructions on how to use it. It has a lot of amenities that will make your stay there easier.
I haven't met the host in person but the communication was ok, he responded quickly whenever I had some questions.
Overall I had a good experience and if I will have to return to Berlin, I will probably chose again Michael's apartment.