We were in this restaurant about a week ago. Without a reservation it was possible to get a table. In the entrance they said we had about 1-1, 5 hour time but after 1 hour the waiter gave a hint to finish as quickly as possible.
Like a few other reviews it was the most negative experience we had in our life in a restaurant (little space around the tables, bad manners waiter, very unfriendly). Especially the last was awful. Because of his behaviour, for the first time we didn't give a tip. The waiter was really angry about that (professional attitude?) and throw the small chance on the table. He didn't say anything to us when we left the restaurant but we heart him saying (I never had this experience before), Anyway, we as well.
The food was indeed nothing special and the price for this to high.
A day later we sent by email our compliant to the restaurant but no reaction at all.
Conclusion: for me and my family the most negative experience during our stay in Berlin.