We were 5 friends staying in Berlin to visit for a few days, and we really enjoyed our trip, Berlin is a lovely city and Alan & Kasia 's apartment is really nice and clean. It's only 100m from the tramway and it's spacious.
We didn't met Alan and Kasia but they were very available to our questions if needed. We met their friend Lisa, who was very nice, she advised us on places to go and made herself available for us to arrange for the keys etc.
Thanks again for the stay !