We had a great time in Berlin and in the apartment. The place is even more beautiful than the photos show, it's cozy, warm, located in a quiet area but super close to nice pubs and bars. The co-host Rafa was very responsive and helpful.
We had one issue which you need to make sure is solved in case you book the place. The heating and hot water didn't work at all during the first night (we arrived pretty late around 11 PM so there was no way of solving it that day) but Rafa took care of it early in the morning. However, heating stopped again in the afternoon due to the timer being set wrongly, so make sure you check this with Rafa before your arrival. Anyway, we were lucky to have very good weather so that wasn't a big issue for us. Definitely a 5-star place!