We stayed here while visiting the Cologne trade fair and had a really lovely experience.
We arrived very late at night, but the 24-hour reception made everything easy (won't deny that the kebab shop next door also helped after our long trip). Check-in was quick and straightforward, and the staff were incredibly friendly and professional, both at night and during the day.
I also loved that the room had all the little extras you might need, even a sewing kit (which I actually needed!). The only thing missing was hair conditioner, which I found a little surprising considering how well equipped everything else was.
Our room overlooked the courtyard, so it was quiet and we even slept with the window open.
We walked to and from the main train station, which was a quick 7-10 minute walk from the hotel.
Overall, a great stay. We would happily come back!