Staying with Andrea and Claire was fantastic. Prenzlauer Berg is a beautiful part of Berlin - leafy streets, lots of coffee shops and bars, vintage clothing shops etc. and their apartment is very close to the U-bahn, which was very easy to use to get around the city. I stayed with Claire and Andrea for 10 days and had a brilliant time. They are very friendly and happy to help out in anyway they can. I will definitely contact them first for accommodation when I am back in Berlin! :)