My stay at Nook was pleasant and comfortable. The hotel is very well located in the heart of Berlin, near U-Bahn and S-Bahn stops and it takes just 10 minutes walk to get to Museumsinsel.
The structure is very modern and all the processes, like check-in/out, are digitalized and you'll get all the instructions to make your life easier.
The customer care is 24/7 available via WhatsApp and it is very excellent and responsive.
If I were in Berlin, I'd stay at Nook again!