We visited before the Hertha BSC match for a quick bite and enjoyed every bite. It's by no means a restaurant - outside bench seats and inside standing only - but for a group of guys wanting a quick and tasty burger it was perfect.
The burgers / fries are succulent and the staff surprisingly friendly in comparison to most German establishments. The price is great and the overall experience felt genuine rather than pretentious which was nice.
Would go back again!