I had really a great stay in Cristina's apartment. I loved the interior design and the bed, which was hugely comfortable! (Especially after a night out partying :D). Cristina was also really fast on answering my emails and always available to help me if I had some problems. The apartment is in a really good position, you can arrive everywhere with the U Bahn in short time, but I'd recommend you to have a good walk if it's a sunny day and you don't have to move too much :D The only thing I "disliked" about my stay, is that I basically could only have a good talk with Cristina on the last day, she's a really friendly and kind person and I hope we can drink something together the next time I come in Berlin!