I'd have rated them 5 stars had the hotel put us in a room in their main building (as I'd requested…read moreon my original e-mail request). I just wanted a view of the world's largest advent calendar from our room window. We were in room 31 in the annex around the corner from the main building. The room was perfectly fine and actually more modernized/renovated than the main building. The room was large with a couch, table, and a couple of chairs, very clean, had a mini-fridge, and a good sized, clean, modern bathroom. We were also able to park our car inside the garage below the room so we didn't have to bother with finding a parking spot (which was a bit more difficult than usual due to Gengebach's Christmas market).
Breakfast was very good despite the fact we did breakfast at 0930, kinda later than usual. There was still plenty of bread, meats, and cheeses to choose from before they started packing up at 1005. And before they took anything away we were asked if we were finished or not. And still we were able to have capuccinos instead of regular coffee.
Don't forget to ask for your Konus Karte upon arrival. The card allows unlimited free local bus and train service in the Black Forest (except for high-speed ICE trains). Gengenbach has a nice Christmas market which was the reason for our visit. From there you can train to Villingen (we did) and/or Freiburg to visit their markets as well.