This has to be one of the worst hotels in Frankfurt! There were a number of broken items in the room, including a broken wardrobe handle & shelf and shower door, and the shower itself did not drain, and vacillated between scorching hot and freezing cold. For most of my stay, the elevator was also out of order.
It wasn't easy to sleep; the curtains were a good foot into the room letting the street light stream in, and one night there was a significant amount of shouting coming from within the hotel. The heating was centrally controlled, and the room was way too hot.
Add to this the non-working internet, and the high cost of the room (>€300/night due to a large exhibition being in town) and there was zero value for money. I checked out and changed hotels for my final night, as I had a meeting which required internet access.
The only plus was the tram stop immediately outside the hotel! Avoid this place.