Please also see update below.
Nice hotel but rooms need an update. Unfriendly staff, especially at the bar. Had to take three tries before I coukd even order a beer. They seemed to look down upon us for not wearing expensive suits.
Ah well, plenty of other hotels in Frankfurt.
Edit: after a new stay, a few weeks later, I am happy to report that things have improved! Staff was very forthcoming and the room was in excellent condition.
I also would like to compliment on the breakfast arrangement. That was really top notch.
Thank you for a nice stay, wir sehen uns!