We spent a week in Berlin and everything was fine. Communications, Appartment Kitchen and Bathroom were great, and we were happy to have a cool atmosphere in the appartement while having 30° outside.
The groundfloor appartement as such, being in the backyard, was somewhat dark but we spent most of the day outside so we didn't bother.
We especially liked the surroundings in the Helmholtz Kiez and the quiet atmosphere in the neighbohood.