I've eaten in a few ethiopian restaurants before. Both here in Berlin and in Sweden. This was by far the best one, the food is great and you get a really big portion for 10€ each if you choose the mixed plate. The staff was very nice and spoke English very well.
Concerning the man mentioning the prostitutes on a street nearby I can not see why that would be something that somehow makes for a bad review of this restaurant. The restaurant is cozy with a great atmosphere.