definitely a good place to stay in Berlin if you look for a cool neighborhood. The place is big, very comfortable for our group. The beds weren't very comfortable, but it worked well. The apartment wasn't very clean, but it didn't affected us.
Everything else was great. The place is very modern, the open spaces good, the outside area very friendly and the location is amazing, in one of the best cool areas in Berlin.
We used the check in system to leave the keys and helped our group in terms of access to the place when we were separated, it was great for us.