Excellent hotel, luxurious breakfasts (which is not typical for Europe), 7 minutes walk from the train station and the cathedral. Tram (there is no metro in Cologne) is a two-minute walk away.
Inside, the hotel is decorated as an art hotel starting from the second floor. Very elegant!
They were fined €100 for smoking in the room, they said that they had to book a smoking room (it turns out that there are still such hotels in Europe)
In general, I highly recommend