We spent one week at Mirko and Tomos' place during our first visit of Berlin and everything was great. The flat was good, tidy and clean and warm (very important cause outside was - 4 C !!!). We did not plan to use the kitchen but actually it turns out to be very useful to have somewhere to cook cause I was sick for my first 2 days of holidays . Tomos and Mirko were very friendly and helpful whenever we have something to ask. They provided us with a map of the area that was very useful with advice for restaurants and bars. We tried the Vietnamese restaurant (From Hanoi with Love) and we really loved it (and was also super cheap!). Neukolln is a very nice multicultural area to stay, very lively with bars, coffee shops and restaurants but not touristic at all. It is very well connected to everywhere you want to go in Berlin, with 2 metro stations at walking distance (Neukolln and Hermanstrasse) with both U-bahn and S-bahn trains. S45 provides a great connection to the airport (runs every 20 minute, less than 30 minute ride!).
Overall we loved Berlin and could definitely recommend Mirko and Tomos' place!