I have microcon, which I have considered selling, as it's something I used mainly for live gigs. But despite limitations, it has certain qualities in sound what I like a lot and very quick and easy ways to achieve those. Unlike some of bigger synths I have which always takes time to operate.
While most appear to laugh at this "toy" monotron, due it's limitations and laughable size & looks, I like it. Basically all (though little) synth work of my past album was done with it. Especially modulation of external sounds can results interesting things. Using it most of all as filter, not for creation of generic oscillations.