Alexander was an excellent host. He and Anni, his co-host, communicated wonderfully with me ahead of my arrival and before check-out. The apartment was just as described and easy to access the metro and had lots of restaurants nearby. There are helpful notes all over the apartment to explain where things are and Alexander also provided 1 adapter for the US plugs.
The only things you may want to be aware of before booking (which Alexander notes, but it is easy to not think of when booking): you must physically be able to climb four flights with your luggage to reach it, as there is no lift; the bathroom and shower are small and a plus size person may find it difficult to maneuver (I'm an XL american size and did ok, but any larger might be tough); there are two bars on the street with people outside smoking/talking until about 12-1 am and the noise can float up - my friend used her white noise app on her phone to cancel it out.
I would recommend this place to my friends if they asked where to stay.