So many things together combined to give this low score.
The reception was outright rude.
Ants in the toilet.
Left over clothes from earlier guests.
Every afternoon to evening the apartment smelled kebab from the restaurant downstairs.
The elevator was not functional until the last two days (4th floor).
On the upside we got late checkout for free (15 instead of 11) and the kebab is really good. Otherwise inly one star would be justified.