The place is simple. You will appreciate the central location. It is quiet despite its proximity to Ku'damm, etc.
The host is great, communicates effectively.
The place - essentially a mid-sized room and an adjacent bath, for which you have to cross a small hallway, has a coffee maker and a small fridge, but that's it.
Making anything other than coffee is essentially impossible, meaning all meals will have to take elsewhere.
While cooking anything in there can't be the goal. a minor rearrangement of the place could yield more comforts for the traveler. The oversized wardrobe strikes as a waste of space given other needs. A small shelf, a couple of plates, bowls, etc (e.g. for cereal, etc) would be more practical. A small TV would also add to the quality of stay. What I would strongly suggest is a different bed. A low-lying futon is not for many under 25 years old.
I am saying all of the above not to be overly critical, but perhaps to suggest minor, inexpensive changes that would double the usefulness of the accommodation.
Thanks for being a great host!