A real fun place and you definitely need a health self confidence not to get intimidated by the big art pieces. (Strang to wake up at night and see oversized women longing for you at the wall.)
Ane be prepared to wake up at night quite a few times, because the hotel is very noisy. The S-Bahn and the train tracks are next to the wall and they really cause lots of rumbling - and all night long.
My wife could stand this only for one night - then we fled to a more quiet place: The Mandala (great hotel at Potsdamer Platz).