This cosy apartment is a great base for visiting Berlin. I'd recommend it just for the amazing high-pressure luxury shower. There's a small bedroom, the bathroom, and a kitchen/living room which has most of the kitchen accessories you'll need, nice sharp knives, and the world's tiniest dishwasher.
I was there for 2 weeks, to concentrate on some writing work, and while the space is cosy and well-equipped, I don't think it's ideal for longer stays or working from home. There is a small table and sofa, but neither are super comfortable. However the internet was fast and reliable.
There are plenty of cafes, restaurants and bars right outside, so if you are not visiting during a pandemic you will have plenty of options to eat out. It's a busy neighbourhood, but the apartment faces the inner courtyard and is very quiet. I was able to sleep with the window open and wake up to the sound of birds singing in the courtyard.