The Monomachine has this ‘dated’ early 2000s digital sound that the digitone doesn’t have. It’s that digital rawness that sets it apart from many other synths. It’s kind of lo-fi and ‘bad in a good way’.
The Digitone on the other hand sounds very very modern. I loved the workflow and intuitiveness of the FM engine. The sounds that came out of it were really good, but ultimately I didn’t think they sounded all that different from those I can get out of Sytrus. That doesn’t mean you can’t get interesting sounds out of it though. It’s sequencer and FX are much better than that on the MM too.
Bottomline is: No, the Digitone does not sound like the Monomachine. Most synths do not. It has that early 2000s digital sound to it that people seem to either love or hate. I don’t know about SOPHIE but when I play around on it I’m always reminded of The Knife (who also used it a lot). It’s why I kept mine when I had to sell most of my gear. I figured I could still get close to the same results from VSTs for the DN but not for the MM.