Another nice thing about this hotel: I have had no problem getting an extra bed/sofa bed put into the room at no cost. Management did not seem to mind 2 adults and 2 children in a standard room. (King/Twin ca. 30 m2) I'm a Globalist and maybe that helped but I think that generally they are used to this drill. I booked for 3 but called in advance and asked if 4 could be accommodated.
(Thinking back I'm trying to recall if the room came with a sofa bed or if an extra bed was added. I just can't remember.)
I found breakfast to be good -- certainly better than what I would get from a kiosk in the airport -- and the restaurant dinner we had on premises was also good.
I agree that this is a solid choice if one is transiting in FRA.