Very noisy! This apartment was in a great central location and good value but you pay the price in lack of sleep. I stayed midweek in mid March and I was kept up into the early hours. Then early in the morning expect someone empting the glass recyling across the street (three mornings in a row). Some noise should be anticpated in the centre of a city but I would recommend ear plugs for this place.
The apartment is not very comfortable either as a previous guest reviewed. The sole heater was broken when I stayed and the bathroom was in need of a clean. Anticipate a student accomadation showroom with no sound insulation and it will be fairly accurate.