I stayed here two weeks ago. It was fairly poor. Arrived around 9pm and checked out around 9am. It is a good representation of a "run down Sheraton". It's massive and the walk from check-in to the room was probably 10 minutes (with luggage).
As a Plat Premier I was upgraded to a room on the club floor. Room was something out of the 70s... really not impressed with the decor or functionality. I've been to many properties in Europe, including Germany, but this was something special. Being Germany, the bed was low, stiff, and horrid, but I anticipated that.
Lounge closes at 11pm so I stopped by at 10:50pm to grab some water before bed. The area seemed open but the cooler was locked. Attendant heard me trying to open it but didn't come by to say anything; I noticed he had looked over then went back to what he was doing in the back. I called him to come over and he said it was now closed. I asked him what time it was and he glibly laughed and said I was right and opened it so I could take some water.
The room was uncomfortably warm and AC was on heating-only and windows locked for safety, so I asked front desk to help. It took 2 hours for them to come with 2 fans to make it tolerable, including me needing to follow up three times to front desk -- because nobody ever came back like they said they would (someone would come, say they need to come back in 15/30 minutes, then never come back, leaving me waiting). Even when I called and asked for the duty manager they didn't tell the duty manager I had asked to see her. Eventually they transferred my call to her so I could ask her directly to come up. She was very apologetic and I ended up moving rooms to a suite a few doors down. (Even though the suite was unsold for the night (by 9pm), they didn't put it for upgrade and simply let it sit empty.) Luckily it was bigger with better airflow and they also now had the fans, which helped a lot.
They didn't have a full front office manager, only a trainee. He was nice enough, but the lack of experience and poor management in the hotel was apparent. I pointed out that there was a dirty tray of food sitting at the entrance of my room clearly from the previous guest and nobody had bothered to pick it up since the time I checked in. Clearing trays and dirty food / dishes at the entrance of rooms should be part of turning over rooms for new guests. (For full clarity, it was the last room on the floor and did not belong to another room).
I skipped the breakfast as I was going to the LH First Class Terminal. I had asked front desk instructions on how to get to the LH FCT and they kept confusing it with the regular check-in area (not surprising, but annoying). Eventually one person seemed to know and the manager said the concierge would walk me outside to point me in the right direction. I walked over to the concierge who had my bags and he hadn't been told he would be helping with this. I went back to the manager who then got a bellman to do it. The bellman was great and actually walked me all the way there, in the cold no less!
Overall, was really disappointing spending 3 hours dealing with issues during a 12 hour stay.