Clean, but industrial-plastic rooms. No nice or luxury products, cheapest lumpy foam pillow, no fridge or tea/coffee, unprofessional desk & wait staff. Our room was ready 2 hours early, but instead of just letting us check in, they wanted €30 extra. Totally average German chain hotel breakfast. Overpriced, perhaps because of the massive water, thermal, & sauna park next door. Go to a real spa hotel if you want an authentic 4-star quality experience, or to a standard chain if you just need a night near Frankfurt.