I have been there at the end of August with my girl.
We initially have some issues to reach the structure, there were so many "baustelle" (work in progress) in Karlsruhe and TomTom went crazy. After calling the hotel they helped us and finally we got there. First good news, reception let us know the park would have been free of charges because of the problems I described.
The room was very clean and spacious, the bed comfortable and the bathroom nice and neat.
Breakfast was very good too. Sweet or savory everything was fresh and there was a wide choice.
It's a bit out of the center but there is a bus stop just in front of the hotel.
Perfect price for such a service.
I totally recommend this hotel.