We've had a fantastic stay at Irene's lovely apartment. It is in a very good neighborhood only two blocks from the S-Bahn, which can take you to Alexanderplatz in about 20-25 mins. Irene and Christopher were very accommodating, they even arranged an earlier check-in for us, because we arrived in the morning; and the communication, too, was very easy all along. The apartment is lovely, quiet and spotless, very tidy and clean. I hope to return to Berlin soon - because I've had a fantastic time there, it's an amazing city - and staying at Irene's place will definitely be by number one option.