You might have felt safe, but objectively, violent crime has risen tremendously in the Bahnhofsviertel since 2020.
Also, human feces and trash everywhere, hoards of crack-smoking junkies around day and night, and the cheap casinos and red-light establishments. Only success in recent times has been that street prostitution has been reduced.

Niddastr. (=street address of the Niu under discussion) is often considered the worst of the entire Bahnhofsviertel. Despite having never stayed at the Niu, I would discourage FT'ers from doing so solely based on its location.