I love mine. Tone is very flexible and highly dependent on player and mouthpiece just like any other sax. I get more of a tenor sound on a tenor mouthpiece and more of an alto sound on a c-mel mouthpiece.
For me, I have to drop a wine cork in the bell to help with the low end gurgle, and have to work to play a clean high G. My altissimo intonation is also a challenge, where my tenor fingerings need to be tweaked a little.
Overall tone is beautiful, and ergos are obviously typical of horns of that era (no G#/C# linkage, in-line keys, etc). I hate the micro tuner since it limits mouthpiece choices to those with short shanks. And none of my alto mouthpieces fit at all.
Lastly, decent, affordable, modern cases are hard to come by. In the C-mel forum on n SOTW, you’ll see a thread about the one I bought and am very happy with. But it cost as much as my horn.
Welcome to the c-melody club.