What they don't tell you is that this hotel has its own function venue, taking up much of the ground, 1st and 2nd floors. The two nights we there, they hosted insanely loud parties until 2am - so loud our bed was literally vibrating! It was very challenging to sleep (despite the ear plugs they provide), there was little by way of apology the next morning except that "they have a very busy December".
The rooms themselves are okay, and the location is great - but next time we are in Cologne we will try a hotel that we can actually sleep in