We stayed at Trudy’s place for the Berlin Marathon and it was perfectly located - far enough out of the centre for it to be quieter but so quick and easy to get into the centre via tram or U Bahn (the stations are right at the end of the road).
The flat is stylish and comfy. There have been comments about the shower which is held up by tape but it works perfectly fine and we had no issues with it.
The flat is a great base for come city exploring!