The room is big, and as seen in the pictures, with a window that lets the sun enters the place. A big mirror, a desk and a closet.
The hosts are extremely friendly and you are allowed to use the items from the kitchen, which is great on a business trip, so you can have breakfast before you leave.
Everything is always clean, and privacy is completely garanteed.
The neighborhood, while it is near Postdamer Platz, so you will have great commuting options and commercial places as the Mall of Berlin, is quiet and residential.
Highly recommended, wether it is for fun or work.
PS: there is an elevator, so you don't have to carry all your luggage upstairs.