We greatly enjoyed our stay in Berlin over Christmas and New Years. The apartment is spacious and light, and well suited for our family (two children in their early 20s). The apartment had everything we needed, and the location is close to shops, restaurants, parks, and many Berlin attractions. We used the apartment as a base to explore Berlin, but also took advantage of the comfortable space and fireplace for long evenings together. Watching the fireworks from the balconies on both sides of the apartment on New Years Eve was spectacular.
One thing to be aware of is that two bedrooms are furnished for young children. Our young adult children slept on mattresses on the floor.