Sven's place is really great! This is now the fourth time I've stayed there, and it's always a great experience. Very clean and orderly, and as much quiet or talk as you want.
It's located in one of the nicer, relaxed and lively bits of Berlin, and it's easy to get many nice places by walking, and otherwise also with the u/s-bahn, which is very close.
Sven is also very kind and supportive of travel and staying logistics.
Well worth visiting.