There are three main advantages - price and location, walking distance from cathedral and parking. Service at reception fine, no complaints. Hotel looks like a normal building with flats, which were bought to rent them as hotel rooms.
Room itself big, 3 beds, very, very comfortable. It was the best in the room. Windows curtains haven't been washed for 'some' time. Bathroom with sink, toilet and shower. Bad air circulation made it stink. One could also smell cigarettes. Wifi worked well. In late evening plenty of people gathering in the corridor or room next to ours, chatting very loudly. In the morning some Turkish woman walked on the roof just below our window and stared at us - that was weird. All hotel guests we met on the corridors were Turkish - very welcoming people.
Summarizing - very good price/cost ratio, I would go there again if visiting Köln next time