This is the noisiest hotel I have ever stayed in. It is positioned at an extremely busy intersection, so even in a room on the 4th floor, the traffic and noise is considerable. The room resounds with the constant rumbling of the tram (Straßenbahn), which also screeches as it turns the corner. To make matters worse, there was construction in the building, which produced a symphony of drilling and pounding sounds beginning around 8am. Impossible even to have a phone conversation. I stayed here for 6 days and was quite actually exhausted from the lack of sleep.
I took note of the hotel manager yelling at the housecleaning staff about not working fast enough (the man didn't even stop his berating as I walked by).
Others have mentioned the breakfast, which is decent. The staff in the breakfast area were always friendly, and if anything needed to be replenished, they were happy to do so.