I didn't get to meet Ross, although we had some friendly chat to make arrangements for the key and so forth, so I can only say this about the apartment: although tiny it is nice and practical; the neighborhood is a real plus since it is quiet, close to "museum island" and all the nice places to see in Berlin.
On the very corner of the building there is a nice pub, which makes it cosy if you want to taste a good German beer in the evening or have a brunch in the morning. Plus on the same street there is a bike rental, perfect to discover the city.
All in all, if I am to return to Berlin I'd book the same place.