I would actually probably give this hotel a "2.5".
The best feature of this hotel was the location...only minutes from the main street in Heidelberg's old town, overlooking the Neckar River (beware of noise from the busy street below, though, if your room overlooks the river).
The hotel staff was very nice & was quite helpful in securing our ride back to the Frankfurt Airport on the Lufthansa shuttle. Since our German was quite limited, we were able to speak in English with the staff members we encountered without a problem.
The continental breakfast was also nice.
However, I don't feel that this hotel merits the high rankings I have seen on various websites. Not all rooms are created equal, as we soon found out by walking by rooms that were being cleaned in the morning. Though very simple in design and decor, our room (on the 3rd floor) reminded me of a college dorm room that had not been cleaned or painted in some time. There were stains on the indoor/outdoor carpet, we were given twin beds that were on opposite sides of the room (our reservation was for a queen/king), and the white walls had scuff marks on them. The bathroom floor was sunken in & clearly needed some improvements. It was impossible to watch the tv from either bed due to where it was placed in the room.
This is definitely a more European-style hotel, but having stayed in many over the years at similar prices in Germany and France, this was by far the least desirable one I have ever stayed in.
Considering that we paid about $100 per night, I don't really feel that the room was up to standard. If I were to do it over again, I would either have communicated with the hotel directly to make sure we were getting the type of room we wanted (I would suggest avoiding the 3rd floor, based on what we saw) or staying at the nearby Crowne Plaza for an extra $50 per night.