If you are on business, this hotel is good.
But if you visit Heidelberg for leisure, this about this:
Good - Good breakfast, restaurant, terrace, a variety of fitness machines and swimming pool (15-17m long), clean room.
Bad: the location is far away from the old city district, and 10 min walk to hauptbahnhof, on the other hand the room is small (deluxe double), and hotel staff are unfriendly (except for those in restaurant), always crowded with business people in conference or something. You can't relax very well... Also the reception staff charged me breakfast fee by mistake. When I pointed it out (after waiting for a long time, there was always a long queue), they said nothing and just threw me a correct bill again.
Well that's it and I'll never use this hotel again.