The apartment is super clean and cozy, location is very good, but it's super noisy which is expected if you plan to stay in the center of Berlin. Unfortunately for me, the air cooling wasn't working, and since the apartment was on the sunny side, it was incredibly hot inside and I wasn't able to sleep. I've contacted Nook support in the middle of the night, and they actually responded, it was 3 AM (!), which was super awesome. Sadly, the issue wasn't resolved, but I'm also not sure if that's something that could be solved fast.
Anyway, if the AC is working, it's a super nice stay despite the noise of the night in Berlin.