We had a great trip to Berlin and it helped that we had a lovely, well located apartment to stay in. The apartment has plenty of space and many rooms to accommodate a large party. It is simply decorated and was very clean and tidy upon arrival. Check in was easy with the downstairs bar holding the keys for us. We never met Marleen (and a couple of minor email questions were never answered) but we were provided with clear instructions on our arrival.
You couldn't get closer to the u-bahn stop which was on a good line which provided easy access to Zoo and to other connecting stations. Took an uber a couple of times too and was relatively cheap from Berlin centre.
We tried a couple of the local bars and really liked Tiree. There are a few shops as well which stay open late which was good to grab a beer and snacks from.
I would recommend Marleen's place to friends and would stay again, thanks for hosting us! :)