I tend to be a bit skeptik towards franchises restaurants in touristical areas, but according to the reviews, the Maredo on Unter den Linden, close to the Brandeburg Tor, is one of the best of the chain in Berlin.
I went there with my parents last time they visited me, it’s just next to the ZDF studios, there’s a nice inner court under a glass roof. My mum loved the salad buffet and the poultry that was very well cook, not too dry.
My dad and I had a very good steak rare cooked and served on a hot stone, so it was kinda still grilling as it was served. They gave us big bibs to protect ourselves from the grease on which it was wriiten something like “bibs are nice, they protect you from the grease, well unfortunately, only your clothes.” The steaks were very tasty and tender, delicious, the fries very crispy. My father also had some gambas with his steak and loved them.
It was a very nice dinner without having to spend too much money, the service was good, the menu is in several languages, friendly staff.
The only 2 bad things: too much salt in the margarita and what they called bearnaise sauce was not really one, but other than that, great!