Almost every things Nothing
Clean The shower booth is too small
Shuttle to the fair easily gets full, and I sometimes needed to take a taxi.
What I liked best during my stay was Niedwald, and top floor (14, in fact 13, but after 12 they jumped to 14:)) with smoking rooms. The breakfeast also was very good.
there are lots of parks and woods around the hotel. its location is very poor in terms of local transport. nearest s-bahn station is kilometers away.
Very clean...very comfortable. Good for people looking for isolation. The only drawback is little off from downtown or main city.