Recently stayed 1 night at Traube Tonbach as part of a conference. Included in the stay was also a dinner at 3 star restaurant Schwarzwaldstube.
Part of my "package" was a stay at a single room, which is noth worth any luxury hotel. I upgraded in advance to a Superior Room, which I thought was with 65 sqm OK for one person and one night.
Check-In was fast and I was shown my room. Indeed it was spacious and more a Junior Suite/ or even suite than a room. The style was not so much my cup of tea, but perhaps fits to the surroundings. The bathroom was adequate but feeled old. Nice view from the balcony. Surcharge was 150,00 €.

The SPA is the real pro, one of the best in Germany.

Also had dinner at 3 star Schwarzwaldstube, here my review:
https://www.flyertalk.com/forum/31139606-post1727.html
Breakfst was OK, but nothing special.
Overall a good stay, but Traube Tonbach is surely (perhaps it was in the past) not the benchmark in Germany.