Whatever you do, get a taxi to the restaurant - don't walk/get public transport, its just easier - and don't be put off that you can't see a entrance clearly. What looks like an industrial unit from the outside is actually the restaurant. Walk towards the river and bare left andit will become clear.
The concept of this restaurant is very interesting, it has a good vibe (music at dinner was very cool Berlin house) and the food is of a good standard with friendly attentive service. Book a table about 9pm and you will be able to stay at your table (if on the outer area) when it turns into a club at 11/11.30pm. I guess the music choice of the club depends on which night you go and which DJ's are on but don't let this put you off going. We didn't stay too long when it turned to a club as it became poptastic but each to their own. I've heard others have been when the music has been better than that.
It really is agreat experience, typical of Berlin. I imagine that it's great in the summer too when you can sit outside, we went in November so it was rather chilly for al fresco dining. I would reccomend it to couples or groups.