If you want the luxury that only the best 5* hotel suite can give you then you should book Christoph's place.
The facilities are amazing and you will have everything you need whether you are staying for business or pleasure.
It is so well located - just 5 minutes walk Wittenbergplatz on U-Bahn Lines U1, U2 and U3 with great connections to all areas of Berlin.
The area is quiet and the 6th floor apartment gives the most spectacular views from both balconies to the west to Teufelsberg and beyond and to the East across the city.
Christoph's communcations were prompt and gave us every detail we needed but ahead of our arrival and during our stay.
We recommend that you go to Bar-Kess for what are probably the best cocktails in Berlin. If you want authentic Italian, then visit Da Lucia. Both are right across the road from the apartment.
You will certainly not be disappointed with this as your choice of place to stay in Berlin.