Location couldn't be better, just 2/3 min walk from Brandenburger Tor, Tiergarten, Reichstag and many other points of interest and it still is a very charming neighbourhood with a very interesting history.
It's very easily accessible from public transport as there are stops for train, subway and bus nearby.
There's a supermarket just across the street and many good restaurants in the same block.
The apartment is very spacious and was perfect for 5 persons.
We didn't get to meet Heinz, but the checkin / checkout process was very simple and everything worked out perfect.
I would definitely recommend a stay here!