Nearer to where I live is Bad Bellingen and Badenweiler, both nice though not comparable to the Friedrichshalle or Bad Liebenzell.
Stuttgart has three main min. baths, the Leuze, Bad Cannstatt and Berg. Berg is still family-owned, and much of the equipment is quite old. It reminds me of the swimming pools when I was a kid in the '60s, wooden booths for changing and so on. The clientele too is very old-world, unlike yuppified Bad Leuze.
Where do you live now? Around Freiburg or Waldshut-Tiengen? A dog's a dog. A Cat's a Cat. (T.S. Eliot)