Overall 3/5 for us because of the hard-as-floor bed and pillows. Even when we asked for softer ones, the owner gave us the same pillows again. We've never slept worse.
Additionally, while everything is very near, please be aware that the building is old and you'll be hearing the guest in the house next to this (we had party people every night), as well as the balcony from the building on the other side (we had a bachelorette party/karaoke). It was horrible, tiring and overall not worth being located in the historical city.
The breakfast is disappointing as well. No fresh bread, just some factory made biscuits and croissants as a substitute. The yoghurt, milk and usual spreads are nice. It can't be that expensive to offer fresh bread, can it?
The cleaning lady is amazing though! Our room was perfectly clean.