Dofo, I have to disagree with you there. If you think that the Steigenberger is suitable for a crew layover, your acceptable standards have fallen to a low ebb. I know some crew from certain American airlines that put cabin crew there, and they hated every minute. It was way below standard ten years ago.
Somewhere online there is a copy of the LH combined cabin and flight crew unions requirements for a layover hotel. They are not excessive, they are simply decent and designed to treat staff as a valued part of the airline. The rest of the airline, sales and marketing on conferences and often including board level used to follow these requirements. It is not rocket science, and is often not based on cost to the company.
As a manager at my previous airline stated, around 20 years ago, "Would you stay with your wife in this hotel?" When a union voice across the table said that he wouldn't stay there with his ex wife, that particular hotel was taken off our list.