The place was wonderful! They were very helpful and gave us instructions on how to get to their place, especially since we arrived late in Berlin and we couldn't wait to get to a comfortable bed and rest :D
They really made us feel like home, we enjoyed the breakfast each morning with them, chatting and asking for recommendations in Berlin. The apartment was sparkling clean and Allen offered us everything we could need.
It's also very well connected, you can find a tram station just in front of the building which takes you to Alexanderplatz in about 20 minutes. Overall, our stay in Berlin was so much better because of Allen and her boyfriend (and their cute baby, of course) :D