This place was if anything even better than the reviews and writeup suggested. The bedrooms were extremely comfortable, the place was very well maintained and, most importantly, Sebastian and his friend (middle-man while Sebastian was away) reached out repeatedly to make sure we were not just okay with the place, but had a good time in Berlin, and got help with anything we needed, in or out of the apartment, so we felt super comfortable reaching out with any questions as they arose. Really nice place to stay. Oh, and the location is in fact great. We easily had access to all the things we wanted to visit across Berlin, and the nearby restaurants and such are great!
BTW, if you are veggie/vegan, Naveena Path around the corner is particularly delicious!