I stayed at Sebastian's for 3 nights and they were great. He has always been really quick on answering everything I asked and always pretty clear and kind.
His apartment is super nice, really sunny and clean, plus it seemed bigger than on the pictures. The room is really big too and would fit 3 people perfectly.
The "problem" with it is that it's on the rooftop, like 6th floor, and has no elevator. This is actually bitter sweet since the building is really beautiful and very well located.