The apartment has an ideal location close to the different metro stations and tourist attractions. It is quiet, cosy and very well heated (which is a great advantage if you come to Berlin in autumn or winter!). Inside you could find anything that you might need for your comfortable stay.
The staff is very friendly and available.
I would only improve the quality of mattresses and pillows. It didn't affect our stay but I believe it could be crucial for someone. Also, Smart TV could be useful but is not something mandatory :)
Furthermore, the apartment is generally clean but with a more intent look, you can notice that it is not crystal clear.
Nevertheless, I enjoyed my stay at Nena Apartments Metropolpark Berlin and would recommend it to anyone for a stay in Berlin!