This HI Express is located near the Frankfurt Main Station. You can walk to the hotel in about 15 minutes, or take a bus #37 from the Main Station, check google maps.
The hotel has been in this location for a long time, and yet it is kept UpToDate, the rooms are clean, the bathroom is nice, good shower with plenty of hot water.
Check-in was friendly, my room had all the amenities, complimentary WIFI, and TV. There is a fitness centre and a buffet breakfast is complimentary. I have stayed at this hotel several times and have never been disappointed.